SI Conversion Calculator

Enter the desired value below in the Enter Quantity field and click the button to perform the metric conversion. If you wish to reverse a conversion begin by entering a value in the Conversion Result field and click to obtain the non SI value.

Table 1. Conversions to Metric Measures

Symbol	Known Quantity	Enter Quantity	Multiply by	To Find	Conversion Result	Metric Symbol	Convert
Length
in	inches		2.54	centimeters		cm
ft	feet		30	centimeters		cm
ft	feet		0.3	meters		m
yd	yards		0.9	meters		m
--	miles		1.6	kilometers		km
Area
sq in	square inches		6.5	square centimeters		cm²
sq ft	square feet		0.09	square meters		m²
sq yd	square yard		0.8	square meters		m²
--	square miles		2.6	square kilometers		km²
Mass
oz	ounces		28	grams		g
lb	pounds		0.45	kilograms		kg
Volume
tsp	teaspoons		5	milliliters		mL
tbsp	tablespoons		15	milliliters		mL
fl oz	fluid ounces		30	milliliters		mL
c	cups		0.24	liters		L
pt	US pints		0.47	liters		L
qt	US quarts		0.95	liters		L
gal	US gallons		3.8	liters		L
cu ft	cubic feet		0.03	cubic meters		m³
cu yd	cubic yard		0.76	cubic meters		m³

Table 2. Selected Laboratory Tests, With Reference Ranges and Conversion Factors

Analyte	Specimen	Reference Range, Conventional Unit	Conventional Unit	Enter Quantity	Conversion Factor (Multiply by)	Reference Range, SI Unit	Conversion Result	SI Unit	Convert
Acetaminophen	Serum, plasma	10-30	µg/mL		6.614	66-200		µmol/L
Acetoacetate	Serum, plasma	<1	mg/dL		97.95	<100		µmol/L
Acetone	Serum, plasma	<1.0	mg/dL		0.172	<0.17		mmol/L
Acid phosphatase	Serum	<5.5	U/L		16.667	<90		nkat/L
Activated partial thromboplastin time (APTT)	Whole blood	25-40	s		1	25-40		s
Adenosine deaminase	Serum	11.5-25.0	U/L		16.667	190-420		nkat/L
Adrenocorticotropic hormone (ACTH)	Plasma	<120	pg/mL		0.22	<26		pmol/L
Alanine	Plasma	1.87-5.89	mg/dL		112.2	210-661		µmol/L
Alanine aminotransferase (ALT)	Serum	10-40	U/L		0.0167	0.17-0.68		µkat/L
Albumin	Serum	3.5-5.0	g/dL		10	35-50		g/L
Alcohol dehydrogenase	Serum	<2.8	U/L		16.667	<47		nkat/L
Aldolase	Serum	1.0-7.5	U/L		0.0167	0.02-0.13		µkat/L
Aldosterone	Serum, plasma	2-9	ng/dL		27.74	55-250		pmol/L
Alkaline phosphatase	Serum	30-120	U/L		0.0167	0.5-2.0		µkat/L
Alprazolam	Serum, plasma	10-50	ng/mL		3.24	32-162		nmol/L
Amikacin	Serum, plasma	20-30	µg/mL		1.708	34-52		µmol/L
α-Aminobutyric acid	Plasma	0.08-0.36	mg/dL		96.97	8-35		µmol/L
δ-Aminolevulinic acid	Serum	15-23	µg/dL		0.0763	1.1-8.0		µmol/L
Amiodarone	Serum, plasma	0.5-2.5	µg/mL		1.55	0.8-3.9		µmol/L
Amitriptyline	Plasma	120-250	ng/mL		3.605	433-903		nmol/L
Ammonia (as nitrogen)	Serum, plasma	15-45	µg/dL		0.714	11-32		µmol/L
Amobarbital	Serum	1-5	µg/mL		4.42	4-22		µmol/L
Amphetamine	Serum, plasma	20-30	ng/mL		7.4	148-222		nmol/L
Amylase	Serum	27-131	U/L		0.0167	0.46-2.23		µkat/L
Androstenedione	Serum	75-205	ng/dL		0.0349	2.6-7.2		nmol/L
Angiotensin I	Plasma	<25	pg/mL		0.772	<15		pmol/L
Angiotensin II	Plasma	10-60	pg/mL		0.957	0.96-58		pmol/L
Angiotensin-converting enzyme	Serum	<40	U/L		16.667	<670		nkat/L
Anion gap Na⁺–(Cl^- + HCO₃^-)	Serum, plasma	8-16	mEq/L		1	8-16		mmol/L
Antidiuretic hormone (ADH)	Plasma	1-5	pg/mL		0.923	0.9-4.6		pmol/L
Antithrombin III	Plasma	21-30	mg/dL		10	210-300		mg/L
α₁-Antitrypsin	Serum	78-200	mg/dL		0.184	14.5-36.5		µmol/L
Apolipoprotein A-I	Serum	80-151	mg/dL		0.01	0.8-1.5		g/L
Apolipoprotein B	Serum, plasma	50-123	mg/dL		0.01	0.5-1.2		g/L
Arginine	Serum	0.37-2.40	mg/dL		57.05	21-138		µmol/L
Arsenic	Whole blood	<2-23	µg/L		0.0133	0.03-0.31		µmol/L
Ascorbic acid (see Vitamin C)
Asparagine	Plasma	0.40-0.91	mg/dL		75.689	30-69		µmol/L
Aspartate aminotransferase (AST)	Serum	10-30	U/L		0.0167	0.17-0.51		µkat/L
Aspartic acid	Plasma	<0.3	mg/dL		75.13	<25		µmol/L
Atrial natriuretic hormone	Plasma	20-77	pg/mL		0.325	6.5-2.5		pmol/L
Bands (see White blood cell count)
Basophils (see White blood cell count)
Base excess	Whole blood	–2 to 3	mEg/L		1	–2 to 3		mmol/L
Bicarbonate	Serum	21-28	mEq/L		1	21-28		mmol/L
Bile acids (total)	Serum	0.3-2.3	µg/mL		2.448	0.73-5.63		µmol/L
Bilirubin, total	Serum	0.3-1.2	mg/dL		17.104	5.0-21.0		µmol/L
Bilirubin, direct (conjugated)	Serum	0.1-0.3	mg/dL		17.104	1.7-5.1		µmol/L
Biotin	Serum	200-500	pg/mL		0.00409	0.82-2.05		nmol/L
Bismuth	Whole blood	1-12	µg/L		4.785	4.8-57.4		nmol/L
Blood gases
Carbon dioxide, Pco₂	Arterial blood	35-45	mm Hg		0.133	4.7-5.9		kPa
pH	Arterial blood	7.35-7.45			1	7.35-7.45
Oxygen, Po₂	Arterial blood	80-100	mm Hg		0.133	11-13		kPa
Brain-type natriuretic peptide (BNP)	Plasma	<167	pg/mL		1	<167		ng/L
Bromide (toxic)	Serum	>1250	µg/mL		0.0125	>15.6		mmol/L
C1 esterase inhibitor	Serum	12-30	mg/dL		10	120-300		mg/L
C3 complement	Serum	1200-1500	µg/mL		0.001	1.2-1.5		g/L
C4 complement	Serum	350-600	µg/mL		0.001	0.35-0.60		g/L
Cadmium	Whole blood	0.3-1.2	µg/L		8.896	2.7-10.7		nmol/L
Caffeine	Serum, plasma	3-15	µg/L		0.515	2.5-7.5		µmol/L
Calcitonin	Plasma	3-26	pg/mL		0.292	0.8-7.6		pmol/L
Calcium, ionized	Serum	4.60-5.08	mg/dL		0.25	1.15-1.27		mmol/L
Calcium, total	Serum	8.2-10.2	mg/dL		0.25	2.05-2.55		mmol/L
Cancer antigen (CA) 125	Serum	<35	U/mL		1	<35		kU/L
Carbamazepine	Serum, plasma	8-12	µg/mL		4.233	34-51		µmol/L
Carbon dioxide (total)	Serum, plasma	22-28	mEq/L		1	22-28		mmol/L
Carboxyhemoglobin, toxic	Whole blood	>20	%		0.01	>0.2		Proportion of 1.0
Carcinoembryonic antigen (CEA)	Serum	<3.0	ng/mL		1	<3.0		µg/L
β-Carotene	Serum	10-85	µg/dL		0.01863	0.2-1.6		µmol/L
Carotenoids	Serum	50-300	µg/dL		0.01863	0.9-5.6		µmol/L
Ceruloplasmin	Serum	20-40	mg/dL		10	200-400		mg/L
Chloramphenicol	Serum	10-25	µg/mL		3.095	31-77		µmol/L
Chlordiazepoxide	Serum, plasma	0.4-3.0	µg/mL		3.336	1.3-10.0		µmol/L
Chloride	Serum, plasma	96-106	mEq/L		1	96-106		mmol/L
Chlorpromazine	Plasma	50-300	ng/mL		3.126	157-942		nmol/L
Chlorpropamide	Plasma	75-250	mg/L		3.61	270-900		µmol/L
Cholecalciferol (see Vitamin D)
Cholesterol (total)
Desirable	Serum, plasma	<200	mg/dL		0.0259	<5.18		mmol/L
Borderline high	Serum, plasma	200-239	mg/dL		0.0259	5.18-6.18		mmol/L
High	Serum, plasma	≥240	mg/dL		0.0259	≥6.21		mmol/L
Cholesterol, high-density (HDL) (low level)	Serum, plasma	<40	mg/dL		0.0259	<1.03		mmol/L
Cholesterol, low-density (LDL) (high level)	Serum, plasma	>160	mg/dL		0.0259	4.144		mmol/L
Cholinesterase	Serum	5-12	mg/L		2.793	14-39		nmol/L
Chorionic gonadotropin (ß-hCG) (nonpregnant)	Serum	5	mIU/mL		1	5		IU/L
Chromium	Whole blood	0.7-28.0	µg/L		19.232	13.4-538.6		nmol/L
Citrate	Serum	1.2-3.0	mg/dL		52.05	60-160		µmol/L
Citrulline	Plasma	0.2-1.0	mg/dL		57.081	12-55		µmol/L
Clonazepam	Serum	10-50	ng/mL		0.317	0.4-15.8		nmol/L
Clonidine	Serum, plasma	1.0-2.0	ng/mL		4.35	4.4-8.7		nmol/L
Clozapine	Serum	200-350	ng/mL		0.003	0.6-1.0		µmol/L
Coagulation factor I	Plasma	0.15-0.35	g/dL		29.41	4.4-10.3		µmol/L
(Fibrinogen)	Plasma	150-350	mg/dL		0.01	1.5-3.5		g/L
Coagulation factor II (prothrombin)	Plasma	70-130	%		0.01	0.70-1.30		Proportion of 1.0
Coagulation factor V	Plasma	70-130	%		0.01	0.70-1.30		Proportion of 1.0
Coagulation factor VII	Plasma	60-140	%		0.01	0.60-1.40		Proportion of 1.0
Coagulation factor VIII	Plasma	50-200	%		0.01	0.50-2.00		Proportion of 1.0
Coagulation factor IX	Plasma	70-130	%		0.01	0.70-1.30		Proportion of 1.0
Coagulation factor X	Plasma	70-130	%		0.01	0.70-1.30		Proportion of 1.0
Coagulation factor XI	Plasma	70-130	%		0.01	0.70-1.30		Proportion of 1.0
Coagulation factor XII	Plasma	70-130	%		0.01	0.70-1.30		Proportion of 1.0
Cobalt	Serum	4.0-10.0	µg/L		16.968	67.9-169.7		nmol/L
Cocaine (toxic)	Serum	>1000	ng/mL		3.297	>3300		nmol/L
Codeine	Serum	10-100	ng/mL		3.34	33-334		nmol/L
Coenzyme Q10 (ubiquinone)	Plasma	0.5-1.5	µg/mL		1	0.5-1.5		mg/L
Copper	Serum	70-140	µg/dL		0.157	44866		µmol/L
Coproporphyrin	Urine	<200	µg/24 h		1.527	<300		µmol/d
Corticotropin	Plasma	<120	pg/mL		0.22	<26		pmol/L
Cortisol	Serum, plasma	5-25	µg/dL		27.588	140-690		nmol/L
Cotinine	Plasma	0-8	µg/L		5.675	0-45		nmol/L
C-peptide	Serum	0.5-2.5	ng/mL		0.331	0.17-0.83		nmol/L
C-reactive protein	Serum	0.08-3.1	mg/L		9.524	0.76-28.5		nmol/L
Creatine	Serum	0.1-0.4	mg/dL		76.25	8-31		µmol/L
Creatine kinase (CK)	Serum	40-150	U/L		0.0167	0.67-2.5		µkat/L
Creatine kinase–MB fraction	Serum	0-7	ng/mL		1	0-7		µg/L
Creatinine	Serum, plasma	0.6-1.2	mg/dL		88.4	53-106		µmol/L
Creatinine clearance	Serum, plasma	75-125	mL/min/1.73m²		0.0167	1.24-2.08		mL/s/m²
Cyanide (toxic)	Whole blood	>1.0	µg/mL		23.24	>23		µmol/L
Cyclic adenosine monophosphate (cAMP)	Plasma	4.6-8.6	ng/mL		3.04	14-26		µmol/L
Cyclosporine	Serum	100-400	ng/mL		0.832	83-333		nmol/L
Cystine	Plasma	0.40-1.40	mg/dL		41.615	16-60		µmol/L
D-dimer	Plasma	<0.5	µg/mL		5.476	<3.0		nmol/L
Dehydroepiandrosterone (DHEA)	Serum	1.8-12.5	ng/mL		3.47	6.2-43.3		nmol/L
Dehydroepiandrosterone sulfate (DHEA-S)	Serum	50-450	µg/dL		0.027	1.6-12.2		µmol/L
Deoxycorticosterone	Serum	2-19	ng/dL		0.0303	61-576		nmol/L
Desipramine	Serum, plasma	50-200	ng/mL		3.754	170-700		nmol/L
Diazepam	Serum, plasma	100-1000	ng/mL		0.0035	0.35-3.51		µmol/L
Digoxin	Plasma	0.5-2.0	ng/mL		1.281	0.6-2.6		nmol/L
Diltiazem	Serum	<200	mg/L		2.412	<480		µmol/L
Disopyramide	Serum, plasma	2.8-7.0	µg/mL		2.946	8.3-22.0		µmol/L
Dopamine	Plasma	<87	pg/mL		6.528	<475		pmol/L
Doxepin	Serum, plasma	30-150	ng/mL		3.579	108-538		nmol/L
Electrophoresis (protein)
Proportion of total protein
Albumin	Serum	52-65	%		0.01	0.52-0.65		Proportion of 1.0
α₁-Globulin	Serum	2.5-5.0	%		0.01	0.025-0.05		Proportion of 1.0
α₂-Globulin	Serum	7.0-13.0	%		0.01	0.07-0.13		Proportion of 1.0
ß-Globulin	Serum	8.0-14.0	%		0.01	0.08-0.14		Proportion of 1.0
γ-Globulin	Serum	12.0-22.0	%		0.01	0.12-0.22		Proportion of 1.0
Concentration
Albumin	Serum	3.2-5.6	g/dL		10	32-56		g/L
α₁ -Globulin	Serum	0.1-0.4	g/dL		10	1-10		g/L
α₂-Globulin	Serum	0.4-1.2	g/dL		10	4-12		g/L
ß-Globulin	Serum	0.5-1.1	g/dL		10	5-11		g/L
γ-Globulin	Serum	0.5-1.6	g/dL		10	5-16		g/L
Eosinophils (see White blood cell count)
Ephedrine (toxic)	Serum	>2	µg/mL		6.052	>12.1		µmol/L
Epinephrine	Plasma	<60	pg/mL		5.459	<330		pmol/L
Erythrocyte count (see Red blood cell count)
Erythrocyte sedimentation rate	Whole blood	0-20	mm/h		1	0-20		mm/h
Erythropoietin	Serum	5-36	IU/L		1	5-36		IU/L
Estradiol (E ₂ )	Serum	30-400	pg/mL		3.671	110-1470		pmol/L
Estriol (E ₃ )	Serum	5-40	ng/mL		3.467	17.4-138.8		nmol/L
Estrogens (total)	Serum	60-400	pg/mL		1	60-400		ng/L
Estrone (E ₁ )	Serum, plasma	1.5-25.0	pg/mL		3.698	5.5-92.5		pmol/L
Ethanol (ethyl alcohol)	Serum, whole blood	<20	mg/dL		0.2171	<4.3		mmol/L
Ethchlorvynol (toxic)	Serum, plasma	>20	µg/mL		6.915	>138		µmol/L
Ethosuximide	Serum	40-100	mg/L		7.084	280-700		µmol/L
Ethylene glycol (toxic)	Serum, plasma	>30	mg/dL		0.1611	>5		mmol/L
Fatty acids (nonesterified)	Serum, plasma	8-25	mg/dL		0.0355	0.28-0.89		mmol/L
Fecal fat (as stearic acid)	Stool	2.0-6.0	g/d		1	2-6		g/24 h
Fenfluramine	Serum	0.04-0.30	µg/mL		4.324	0.18-1.30		µmol/L
Fentanyl	Serum	0.01-0.10	µg/mL		2.972	0.02-0.30		µmol/L
Ferritin	Serum	15-200	ng/mL		2.247	33-450		pmol/Lng/mL
α₁-Fetoprotein	Serum	<10	ng/mL		1	<10		µg/L
Fibrin degradation products	Plasma	<10	µg/mL		1	<10		mg/L
Fibrinogen	Plasma	200-400	mg/dL		0.0294	5.8-11.8		µmol/L
Flecanide	Serum, plasma	0.2-1.0	µg/mL		2.413	0.5-2.4		µmol/L
Fluoride	Whole blood	<0.05	mg/dL		0.5263	<0.027		mmol/L
Fluoxetine	Serum	200-1100	ng/mL		0.00323	0.65-3.56		µmol/L
Flurazepam (toxic)	Serum, plasma	>0.2	µg/mL		2.5	>0.5		µmol/L
Folate (folic acid)	Serum	3-16	ng/mL		2.266	7-36		nmol/L
Follicle-stimulating hormone (FSH)	Serum, plasma	1-100	mIU/mL		1	1-100		IU/L
Fructosamine	Serum	36-50	mg/L		5.581	200-280		mmol/L
Fructose	Serum	1-6	mg/dL		55.506	55-335		µmol/L
Galactose	Serum, plasma	<20	mg/dL		0.0555	<1.10		mmol/L
Gastrin	Serum	25-90	pg/mL		0.481	12-45		pmol/L
Gentamicin	Serum	6-10	µg/mL		2.09	12-21		µmol/L
Glucagon	Plasma	20-100	pg/mL		1	20-100		ng/L
Glucose	Serum	70-110	mg/dL		0.0555	3.9-6.1		mmol/L
Glucose-6-phosphate dehydrogenase	Whole blood	10-14	U/g hemoglobin		0.0167	0.17-0.24		nkat/g hemoglobin
Glutamic acid	Plasma	0.2-2.8	mg/dL		67.967	15-190		µmol/L
Glutamine	Plasma	6.1-10.2	mg/dL		68.423	420-700		µmol/L
γ-Glutamyltransferase (GGT)	Serum	2-30	U/L		0.0167	0.03-0.51		µkat/L
Glutethimide	Serum	2-6	µg/mL		4.603	9-28		µmol/L
Glycerol (free)	Serum	0.3-1.72	mg/dL		0.1086	0.32-0.187		mmol/L
Glycine	Plasma	0.9-4.2	mg/dL		133.2	120-560		µmol/L
Gold	Serum	<10	µg/dL		50.77	<500		nmol/L
Growth hormone (GH)	Serum	0-18	ng/mL		1	0-18		µg/L
Haloperidol	Serum, Plasma	6-24	ng/mL		2.66	16-65		nmol/L
Haptoglobin	Serum	26-185	mg/dL		10	260-1850		mg/L
Hematocrit	Whole blood	41-50	%		0.01	0.41-0.50		Proportion of 1.0
Hemoglobin	Whole blood	14.0-17.5	g/dL		10	140-175		g/L
Mean corpuscular hemoglobin (MCH)	Whole blood	26-34	pg/cell		1	26-34		pg/cell
Mean corpuscular hemoglobin concentration (MCHC)	Whole blood	33-37	g/dL		10	330-370		g/L
Mean corpuscular volume (MCV)	Whole blood	80-100	µm³		1	80-100		fL
Hemoglobin A _1c (glycated hemoglobin)	Whole blood	4-7	% of total hemoglobin		0.01	0.04-0.07		Proportion of total hemoglobin
Hemoglobin A ₂	Whole blood	2.0-3.0	%		0.01	0.02-0.03		Proportion of 1.0
Histamine	Plasma	0.5-1.0	µg/L		8.997	4.5-9.0		nmol/L
Histidine	Plasma	0.5-1.7	mg/dL		64.45	32-110		µmol/L
Homocysteine	Plasma	0.68-2.02	mg/L		7.397	5-15		µmol/L
Homovanillic acid	Urine	1.4-8.8	mg/24 h		5.489	8-48		µmol/d
Hydrocodone	Serum	<0.02	µg/mL		3.34	<0.06		µmol/L
Hydromorphone	Serum	0.008-0.032	µg/mL		3504	28-112		nmol/L
β-Hydroxybutyric acid	Plasma	<3.0	mg/dL		96.06	<300		µmol/L
5-Hydroxyindoleacetic acid (5-HIAA)	Urine	2-6	mg/24 h		5.23	10.4-31.2		µmol/d
Hydroxyproline	Plasma	<0.55	mg/dL		76.266	<42		µmol/L
Ibuprofen	Serum	10-50	µg/mL		4.848	50-243		µmol/L
Imipramine	Plasma	150-250	ng/mL		3.566	536-893		nmol/L
Immunoglobulin A (IgA)	Serum	40-350	mg/dL		10	400-3500		mg/L
Immunoglobulin D (IgD)	Serum	0-8	mg/dL		10	0-80		mg/L
Immunoglobulin E (IgE)	Serum	0-1500	µg/L		0.001	0-1.5		mg/L
Immunoglobulin G (IgG)	Serum	650-1600	mg/dL		0.01	6.5-16.0		g/L
Immunoglobulin M (IgM)	Serum	54-300	mg/dL		10	550-3000		mg/L
Insulin	Serum	2.0-20	µIU/mL		6.945	14-140		pmol/L
Insulinlike growth factor	Serum	130-450	ng/mL		0.131	18-60		nmol/L
Iodine	Serum	58-77	µg/L		7.88	450-580		nmol/L
Iron	Serum	60-150	µg/dL		0.179	10.7-26.9		µmol/L
Iron-binding capacity	Serum	250-450	µg/dL		0.179	44.8-80.6		µmol/L
Isoleucine	Plasma	0.5-1.3	mg/dL		76.236	40-100		µmol/L
Isoniazid	Plasma	1-7	µg/mL		7.291	7-51		µmol/L
Isopropanol (toxic)	Serum, plasma	>400	mg/L		0.0166	>6.64		mmol/L
Kanamycin	Serum, plasma	25-35	µg/mL		2.08	52-72		µmol/L
Ketamine	Serum	0.2-6.3	µg/mL		4.206	0.8-26		µmol/L
17-Ketosteroids	Urine	3-12	mg/24 h		3.33	10-42		µmol/d
Lactate	Plasma	5.0-15	mg/dL		0.111	0.6-1.7		mmol/L
Lactate dehydrogenase (LDH)	Serum	100-200	U/L		0.0167	1.7-3.4		µkat/L
LDH isoenzymes
LD₁	Serum	17-27	%		0.01	0.17-0.27		Proportion of 1.0
LD₂	Serum	27-37	%		0.01	0.27-0.37		Proportion of 1.0
LD₃	Serum	18-25	%		0.01	0.18-0.25		Proportion of 1.0
LD₄	Serum	3-8	%		0.01	0.03-0.08		Proportion of 1.0
LD₅	Serum	0-5	%		0.01	0-0.05		Proportion of 1.0
Lead	Serum	<10-20	µg/dL		0.0483	<0.5-1.0		µmol/L
Leucine	Plasma	1.0-2.3	mg/dL		76.237	75-175		µmol/L
Leukocytes (see White blood cell count)
Lidocaine	Serum, plasma	1.5-6.0	µg/mL		4.267	6.4-25.6		µmol/L
Lipase	Serum	31-186	U/L		0.0167	0.5-3.2		µkat/L
Lipoprotein(a) [Lp(a)]	Serum	10-30	mg/dL		0.0357	0.35-1.0		µmol/L
Lithium	Serum	0.6-1.2	mEq/L		1	0.6-1.2		mmol/L
Lorazepam	Serum	50-240	ng/mL		3.114	156-746		nmol/L
Luteinizing hormone (LH)	Serum, plasma	1-104	mIU/mL		1	1-104		IU/L
Lycopene	Serum	0.15-0.25	mg/L		1.863	0.28-0.46		µmol/L
Lymphocytes (see White blood cell count)
Lysergic acid diethylamide	Serum	<0.004	µg/mL		3726	<15		nmol/L
Lysine	Plasma	1.2-3.5	mg/dL		68.404	80-240		µmol/L
Lysozyme	Serum, plasma	0.4-1.3	mg/dL		10	4-13		mg/L
Magnesium	Serum	1.3-2.1	mEq/L		0.5	0.65-1.05		mmol/L
Manganese	Whole blood	10-12	µg/L		18.202	182-218		nmol/L
Maprotiline	Plasma	200-600	ng/mL		1	200-600		µg/L
Melatonin	Serum	10-15	ng/L		4.305	45-66		pmol/L
Meperidine	Serum, plasma	400-700	ng/mL		4.043	1620-2830		nmol/L
Mercury	Serum	<5	µg/L		4.985	<25		nmol/L
Metanephrine (total)	Urine	<1.0	mg/24 h		5.07	<5		µmol/d
Metformin	Serum	1-4	µg/mL		7.742	8-30		µmol/L
Methadone	Serum, plasma	100-400	ng/mL		0.00323	0.32-1.29		µmol/L
Methamphetamine	Serum	0.01-0.05	µg/mL		6.7	0.07-0.34		µmol/L
Methanol	Plasma	<200	µg/mL		0.0312	<6.2		mmol/L
Methaqualone	Serum, plasma	2-3	µg/mL		4	8-12		µmol/L
Methemoglobin	Whole blood	<0.24	g/dL		155	<37.2		µmol/L
Methemoglobin	Whole blood	<1.0	% of total hemoglobin		0.01	<0.01		Proportion of total hemoglobin
Methicillin	Serum	8-25	mg/L		2.636	22-66		µmol/L
Methionine	Plasma	0.1-0.6	mg/dL		67.02	6-40		µmol/L
Methotrexate	Serum, plasma	0.04-0.36	mg/L		2200	90-790		nmol/L
Methyldopa	Plasma	1-5	µg/mL		4.735	5.0-25		µmol/L
Metoprolol	Serum, plasma	75-200	ng/mL		3.74	281-748		nmol/L
ß ₂ -Microglobulin	Serum	1.2-2.8	mg/L		1	1.2-2.8		mg/L
Morphine	Serum, plasma	10-80	ng/mL		3.504	35-280		nmol/L
Myoglobin	Serum	19-92	µg/L		0.0571	1.0-5.3		nmol/L
Naproxen	Serum	26-70	µg/mL		4.343	115-300		µmol/L
Niacin (nicotinic acid)	Urine	2.4-6.4	mg/24 h		7.3	17.5-46.7		µmol/d
Nickel	Whole blood	1.0-28.0	µg/L		17.033	17-476		nmol/L
Nicotine	Plasma	0.01-0.05	mg/L		6.164	0.062-0.308		µmol/L
Nitrogen (nonprotein)	Serum	20-35	mg/dL		0.714	14.3-25.0		mmol/L
Nitroprusside (as thiocyanate)		6-29	µg/mL		17.2	103-500		µmol/L
Norepinephrine	Plasma	110-410	pg/mL		5.911	650-2423		pmol/L
Nortriptyline	Serum, plasma	50-150	ng/mL		3.797	190-570		nmol/L
Ornithine	Plasma	0.4-1.4	mg/dL		75.666	30-106		µmol/L
Osmolality	Serum	275-295	mOsm/kg		1	275-295		mmol/kg
Osteocalcin	Serum	3.0-13.0	ng/mL		1	3.0-13.0		µg/L
Oxalate	Serum	1.0-2.4	mg/mL		11.107	11-27		µmol/L
Oxazepam	Serum, plasma	0.2-1.4	µg/mL		3.487	0.7-4.9		µmol/L
Oxycodone	Serum	10-100	ng/mL		3.171	32-317		nmol/L
Oxygen, partial pressure (Po ₂ )	Arterial blood	80-100	mm Hg		0.133	11-13		kPa
Paraquat	Whole blood	0.1-1.6	µg/mL		5.369	0.5-8.5		µmol/L
Parathyroid hormone	Serum	10-65	pg/mL		1	10-65		ng/L
Pentobarbital	Serum, plasma	1-5	µg/mL		4.439	4.0-22		µmol/L
Pepsinogen	Serum	28-100	ng/mL		1	28-100		µg/L
pH (see Blood gases)
Phencyclidine (toxic)	Serum, plasma	90-800	ng/mL		4.109	370-3288		nmol/L
Phenobarbital	Serum, plasma	15-40	µg/mL		4.31	65-172		µmol/L
Phenylalanine	Plasma	0.6-1.5	mg/dL		60.544	35-90		µmol/L
Phenylpropanolamine	Serum	0.05-0.10	µg/mL		6613	330-660		nmol/L
Phenytoin	Serum, plasma	10-20	mg/L		3.968	40-79		µmol/L
Phosphorus (inorganic)	Serum	2.3-4.7	mg/dL		0.323	0.74-1.52		mmol/L
Placental lactogen	Serum	0.5-1.1	µg/mL		46.296	23-509		nmol/L
Plasminogen (antigenic)	Plasma	10-20	mg/dL		0.113	1.1-2.2		µmol/L
Plasminogen activator inhibitor	Plasma	4-40	ng/mL		19.231	75-750		pmol/L
Platelet count (thrombocytes)	Whole blood	150-350	×10³/µL		1	150-350		×10⁹/L
Porphyrins (total)	Urine	20-120	µg/L		1.203	25-144		nmol/L
Potassium	Serum	3.5-5.0	mEq/L		1	3.5-5.0		mmol/L
Prealbumin	Serum	19.5-35.8	mg/dL		10	195-358		mg/L
Pregnanediol	Urine	<2.6	mg/24 h		3.12	<8		µmol/d
Pregnanetriol	Urine	<2.5	mg/24 h		2.972	<7.5		µmol/d
Primidone	Serum, plasma	5-12	µg/mL		4.582	23-55		µmol/L
Procainamide	Serum, plasma	4-10	µg/mL		4.25	17-42		µmol/L
Progesterone	Serum	0.15-25	ng/mL		3.18	0.5-79.5		nmol/L
Prolactin	Serum	3.8-23.2	µg/L		43.478	165-1010		pmol/L
Proline	Plasma	1.2-3.9	mg/dL		86.858	104-340		µmol/L
Propoxyphene	Plasma	0.1-0.4	µg/mL		2.946	0.3-1.2		µmol/L
Propranolol	Serum	50-100	ng/mL		3.856	193-386		nmol/L
Prostate-specific antigen	Serum	<4.0	ng/mL		1	<4.0		µg/L
Protein (total)	Serum	6.0-8.0	g/dL		10	60-80		g/L
Prothrombin time (PT)	Plasma	10-13	s		1	10-13		s
Protoporphyrin	Red blood cells	15-50	µg/dL		0.0178	0.27-0.89		µmol/L
Protriptyline	Serum, plasma	70-250	µg/dL		3.787	266-950		nmol/L
Pyridoxine (see Vitamin B₆)
Pyruvate	Plasma	0.5-1.5	mg/dL		113.56	60-170		µmol/L
Quinidine	Serum	2.0-5.0	µg/mL		3.082	6.2-15.4		µmol/L
Red blood cell count	Whole blood	3.9-5.5	×10⁶/µL		1	3.9-5.5		×10¹²/L
Renin	Plasma	30-40	pg/mL		0.0237	0.7-1.0		pmol/L
Reticulocyte count	Whole blood	25-75	×10³/µL		1	25-75		×10⁹/L
Reticulocyte count	Whole blood	0.5-1.5	% of red blood cells		0.01	0.005-0.015		Proportion of red blood cells
Retinol (see Vitamin A)
Riboflavin (see Vitamin B₂)
Rifampin	Serum	4-40	mg/L		1.215	5-49		µmol/L
Salicylates	Serum, plasma	150-300	µg/mL		7.24	1086-2172		µmol/L
Selenium	Serum, plasma	58-234	µg/L		0.0127	0.74-2.97		µmol/L
Serine	Plasma	0.7-2.0	mg/dL		95.156	65-193		µmol/L
Serotonin (5-hydroxytryptamine)	Whole blood	50-200	ng/mL		0.00568	0.28-1.14		µmol/L
Sex hormone-binding globulin	Serum	1.5-2.0	µg/mL		8.896	13-17		nmol/L
Sodium	Serum	136-142	mEq/L		1	136-142		mmol/L
Somatomedin C (Insulinlike growth factor)	Serum	130-450	ng/mL		0.131	18-60		nmol/L
Somatostatin	Plasma	<25	pg/mL		0.611	<15		pmol/L
Streptomycin	Serum	7-50	mg/L		1.719	12-86		µmol/L
Strychnine	Whole blood	<0.5	mg/L		2.99	<1.5		µmol/L
Substance P	Plasma	<240	pg/mL		0.742	<180		pmol/L
Sulfate	Serum	10-32	mg/L		31.188	310-990		µmol/L
Sulfmethemoglobin	Whole blood	<1.0	% of total hemoglobin		0.01	<0.010		Proportion of total hemoglobin
Taurine	Plasma	0.3-2.1	mg/dL		79.91	24-168		µmol/L
Testosterone	Serum	300-1200	ng/dL		0.0347	10.4-41.6		nmol/L
Tetrahydrocannabinol	Serum	<0.20	µg/mL		3.18	<0.60		µmol/L
Theophylline	Serum, plasma	10-20	µg/mL		5.55	56-111		µmol/L
Thiamine (see Vitamin B₁ )
Thiopental	Serum, plasma	1-5	µg/mL		4.144	4.1-20.7		µmol/L
Thioridazine	Serum, plasma	1.0-1.5	µg/mL		2.699	2.7-4.1		µmol/L
Threonine	Plasma	0.9-2.5	mg/dL		84	75-210		µmol/L
Thrombin time	Plasma	16-24	s		1	16.24		s
Thrombocytes (see Platelet count)
Thyroglobulin	Serum	3-42	ng/mL		1	3-42		µg/L
Thyrotropin	Serum	0.4-4.2	mIU/L		1	0.4-4.2		mIU/L
Thyroxine, free (FT ₄ )	Serum	0.9-2.3	ng/dL		12.871	12-30		pmol/L
Thyroxine, total (T ₄ )	Serum	5.5-12.5	µg/dL		12.871	71-160		nmol/L
Thyroxine-binding globulin	Serum	16.0-24.0	µg/mL		17.094	206-309		nmol/L
Tissue plasminogen activator	Plasma	<0.04	IU/mL		1000	<40		IU/L
Tobramycin	Serum, plasma	5-10	µg/mL		2.139	10-21		µmol/L
Tocainide	Serum	4-10	µg/mL		5.201	21-52		µmol/L
α-Tocopherol (see Vitamin E)
Tolbutamide	Serum	80-240	µg/mL		3.7	296-888		µmol/L
Transferrin	Serum	200-400	mg/dL		0.123	2.5-5.0		µmol/L
Triglycerides	Serum	<160	mg/dL		0.0113	1.8		mmol/L
Triiodothyronine, free (FT₃)	Serum	130-450	pg/dL		0.0154	2.0-7.0		pmol/L
Triiodothyronine, total (T₃)	Serum	60-180	ng/dL		0.0154	0.92-2.76		nmol/L
Troponin I	Serum	0-0.4	ng/mL		1	0-0.4		µg/L
Troponin T	Serum	0-0.1	ng/mL		1	0-0.1		µg/L
Tryptophan	Plasma	0.5-1.5	mg/dL		48.967	25-73		µmol/L
Tyrosine	Plasma	0.4-1.6	mg/dL		55.19	20-90		µmol/L
Urea nitrogen	Serum	8-23	mg/dL		0.357	2.9-8.2		mmol/L
Uric acid	Serum	4.0-8.0	mg/dL		59.485	240-480		µmol/L
Urobilinogen	Urine	1-3.5	mg/24 h		1.7	1.7-5.9		µmol/d
Valine	Plasma	1.7-3.7	mg/dL		85.361	145-315		µmol/L
Valproic acid	Serum, plasma	50-100	µg/mL		6.934	346-693		µmol/L
Vancomycin	Serum, plasma	20-40	µg/mL		0.69	14-28		µmol/L
Vanillylmandelic acid (VMA)	Urine	2.1-7.6	mg/24 h		5.046	11-38		µmol/d
Vasoactive intestinal polypeptide	Plasma	<50	pg/mL		0.296	<15		pmol/L
Vasopressin	Plasma	1.5-2.0	pg/mL		0.923	1.0-2.0		pmol/L
Verapamil	Serum, Plasma	100-500	ng/mL		2.2	220-1100		nmol/L
Vitamin A (retinol)	Serum	30-80	µg/dL		0.0349	1.05-2.80		µmol/L
Vitamin B₁ (thiamine)	Serum	0-2	µg/dL		29.6	0-75		nmol/L
Vitamin B₂ (riboflavin)	Serum	4-24	µg/dL		26.6	106-638		nmol/L
Vitamin B₃	Whole blood	0.2-1.8	µg/mL		4.56	0.9-8.2		µmol/L
Vitamin B₆ (pyridoxine)	Plasma	5-30	ng/mL		4.046	20-121		nmol/L
Vitamin B₁₂	Serum	160-950	pg/mL		0.7378	118-701		pmol/L
Vitamin C (ascorbic acid)	Serum	0.4-1.5	mg/dL		56.78	23-85		µmol/L
Vitamin D (1,25 dihydroxyvitamin D)	Serum	25-45	pg/mL		2.6	60-108		pmol/L
Vitamin D (25-hydroxyvitamin D)	Plasma	14-60	ng/mL		2.496	35-150		nmol/L
Vitamin E (a-tocopherol)	Serum	43221	µg/mL		23.22	15676		µmol/L
Vitamin K	Serum	0.13-1.19	ng/mL		2.22	0.29-2.64		nmol/L
Warfarin	Serum, plasma	1.0-10	µg/mL		3.247	3.2-32.4		µmol/L
White blood cell count	Whole blood	4500-11000	/µL		0.001	4.5-11.0		×10⁹/L
Differential count
Neutrophils-segmented	Whole blood	1800-7800	/µL		0.001	1.8-7.8		×10⁹/L
Neutrophils-bands	Whole blood	0-700	/µL		0.001	0-0.70		×10⁹/L
Lymphocytes	Whole blood	1000-4800	/µL		0.001	1.0-4.8		×10⁹/L
Monocytes	Whole blood	0-800	/µL		0.001	0-0.80		×10⁹/L
Eosinophils	Whole blood	0-450	/µL		0.001	0-0.45		×10⁹/L
Basophils	Whole blood	0-200	/µL		0.001	0-0.20		×10⁹/L
Differential count (number fraction)
Neutrophils-segmented	Whole blood	56	%		0.01	0.56		Proportion of 1.0
Neutrophils-bands	Whole blood	3	%		0.01	0.03		Proportion of 1.0
Lymphocytes	Whole blood	34	%		0.01	0.34		Proportion of 1.0
Monocytes	Whole blood	4	%		0.01	0.04		Proportion of 1.0
Eosinophils	Whole blood	2.7	%		0.01	0.027		Proportion of 1.0
Basophils	Whole blood	0.3	%		0.01	0.003		Proportion of 1.0
Zidovudine	Serum, plasma	0.15-0.27	µg/mL		3.7	0.56-1.01		µmol/L
Zinc	Serum	75-120	µg/dL		0.153	11.5-18.5		µmol/L

^aThe laboratory values and reference ranges are provided for illustration only and are not intended to be comprehensive or definitive. Each laboratory determines its own values, and reference ranges are highly method dependent. Reference values given are for adults. For some entries for which specific molecular masses are not known (eg, proteins), reference values in SI are given as mass amounts per liter.

The information in this table is adapted from and based on the following sources: (1) Kratz A, Ferraro M, Sluss PM, Lewandrowski KB. Laboratory reference values. N Engl J Med. 2004;351(15):1548-1563; (2) Young DS, Huth EJ. SI Units for Clinical Measurement. Philadelphia, PA: American College of Physicians; 1998; (3) Henry JB, ed. Clinical Diagnosis and Management by Laboratory Methods. 20th ed. Philadelphia, PA: WB Saunders; 2001; (4) Kasper DL, Braunwald E, Fauci AS, et al, eds. Harrison's Principles of Internal Medicine, 16th ed. New York, NY: McGraw Hill; 2004; and (5) Goldman L, Ausiello D. Cecil Textbook of Medicine. 22nd ed. Philadelphia, PA: WB Saunders; 2004.

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date: 22 July 2018