Updated September 28, 2001.
Conventional units of measure are preferred, with Système International (SI) units expressed secondarily (in parentheses). To convert values from conventional units to SI units, multiply by the conversion factor.
| Component |
Conventional Unit |
Conversion Factor |
SI Unit |
| Acetaminophen | µg/mL | 6.62 | µmol/L |
| Acetoacetic acid | mg/dL | 0.098 | mmol/L |
| Acetone | mg/dL | 0.172 | mmol/L |
| Acid phosphatase | units/L | 1.0 | U/L |
| Alanine | mg/dL | 112.2 | µmol/L |
| Alanine aminotransferase (ALT) | units/L | 1.0 | U/L |
| Albumin | g/dL | 10 | g/L |
| Alcohol dehydrogenase | units/L | 1.0 | U/L |
| Aldolase | units/L | 1.0 | U/L |
| Aldosterone | ng/dL | 0.0277 | nmol/L |
| Alkaline phosphatase | units/L | 1.0 | U/L |
| Aluminum | ng/mL | 0.0371 | µmol/L |
| Aminobutyric acid | mg/dL | 97 | µmol/L |
| Amitriptyline | ng/mL | 3.61 | nmol/L |
| Ammonia (as NH3) (Dual report) |
µg/dL | 0.587 | µmol/L |
| Amylase | units/L | 1.0 | U/L |
| Androstenedione | ng/dL | 0.0349 | nmol/L |
| Angiotensin I | pg/mL | 0.772 | pmol/L |
| Angiotensin II | pg/mL | 0.957 | pmol/L |
| Anion gap | mEq/L | 1.0 | mmol/L |
| Antidiuretic hormone | pg/mL | 0.923 | pmol/L |
| Antithrombin III | mg/dL | 10 | mg/L |
 1-Antitrypsin(Dual report) |
mg/dL | 0.184 | µmol/L |
| Apolipoprotein A | mg/dL | 0.01 | g/L |
| Apolipoprotein B | mg/dL | 0.01 | g/L |
| Arginine | mg/dL | 57.4 | µmol/L |
| Asparagine | mg/dL | 75.7 | µmol/L |
| Aspartate aminotransferase (AST) | units/L | 1.0 | U/L |
| Bicarbonate | mEq/L | 1.0 | mmol/L |
| Bilirubin (Dual report) |
mg/dL | 17.1 | µmol/L |
| Blood gases (arterial) | |||
| Paco2 | mm Hg | 1.0 | mm Hg |
| pH | pH units | 1.0 | pH units |
| Pao2 | mm Hg | 1.0 | mm Hg |
| Bromide | mg/dL | 0.125 | mmol/L |
| C-peptide | ng/mL | 0.333 | nmol/L |
| C1 esterase inhibitor | mg/dL | 10 | mg/L |
| C3 complement | mg/mL | 0.01 | g/L |
| C4 complement | mg/mL | 0.01 | g/L |
| Calcitonin | pg/mL | 1.0 | ng/L |
| Calcium (Dual report) |
mg/dL | 0.25 | mmol/L
|
| mEq/L | 0.50 | mmol/L | |
| Carbon dioxide | mEq/L | 1.0 | mmoI/L |
| Carboxyhemoglobin | % of hemoglobin saturation |
0.01 | Proportion of hemoglobin saturation |
| Carotene | µg/dL | 0.0186 | µmol/L |
| Ceruloplasmin | mg/dL | 10 | mg/L |
| Chloride | mEq/L | 1.0 | mmol/L |
| Cholesterol (Dual report) |
mg/dL | 0.0259 | mmol/L |
| Citrate | mg/dL | 52.05 | µmol/L |
| Copper | µg/dL | 0.157 | µmoI/L |
| Coproporphyrins (urine) | µg/24 hr | 1.527 | nmol/d |
| Corticotropin (ACTH) | pg/mL | 0.22 | pmol/L |
| Cortisol | µg/dL | 27.59 | nmol/L |
| Cotinine | ng/mL | 5.68 | nmol/L |
| Creatine | mg/dL | 76.26 | µmol/L |
| Creatine kinase (CK) | units/L | 1.0 | U/L |
| Creatinine (Dual report) |
mg/dL | 88.4 | µmol/L |
| Creatinine clearance (Dual report) |
mL/min | 0.0167 | mL/s |
| Cyanide | mg/L | 23.24 | µmol/L |
| Dehydroepiandrosterone (DHEA) | ng/mL | 3.47 | nmol/L |
| Desipramine | ng/mL | 3.75 | nmol/L |
| Diazepam | µg/mL | 3.512 | µmol/L |
| Digoxin (Dual report) |
ng/mL | 1.281 | nmol/L |
| Epinephrine | pg/mL | 5.46 | pmol/L |
| Erythrocyte sedimentation rate | mm/h | 1.0 | mm/h |
| Estradiol (Dual report) |
pg/mL | 3.671 | pmol/L |
| Estriol | ng/mL | 3.467 | nmol/L |
| Estrone | ng/dL | 37 | pmoI/L |
| Ethanol (ethyl alcohol) | mg/dL | 0.217 | mmol/L |
| Ethylene glycol | mg/L | 16.11 | µmol/L |
| Ferritin | ng/mL | 2.247 | pmol/L |
| -Fetoprotein |
ng/mL | 1.0 | µg/L |
| Fibrinogen | mg/dL | 0.0294 | µmol/L |
| Fluoride | µg/mL | 52.6 | µmol/L |
| Folate | ng/mL | 2.266 | nmol/L |
| Follicle-stimulating hormone | mIU/mL | 1.0 | IU/L |
| Fructose | mg/dL | 55.5 | µmol/L |
| Galactose | mg/dL | 55.506 | µmol/L |
| Glucagon | pg/mL | 1.0 | ng/L |
| Glucose (Dual report) |
mg/dL | 0.0555 | mmol/L |
| Glutamine | mg/dL | 68.42 | µmol/L |
 -Glutamyltransferase (GGT) |
units/L | 1.0 | U/L |
| Glycated hemoglobin (glycosylated hemoglobin A1, A1C) |
% of total hemoglobin |
0.01 | Proportion of total hemoglobin |
| Glycerol (free) | mg/dL | 108.59 | µmol/L |
| Glycine | mg/dL | 133.3 | µmol/L |
| Haptoglobin | mg/dL | 0.10 | µmol/L |
| Hematocrit | % | 0.01 | Proportion of 1.0 |
| Hemoglobn (whole blood) Mass concentration |
g/dL | 10.0 | g/L |
| High-density lipoprotein cholesterol (HDL-C) (Dual report) |
mg/dL | 0.0259 | mmol/L |
| Histidine | mg/dL | 64.45 | µmol/L |
| Homocysteine (total) | mg/L | 7.397 | µmol/L |
| Human chorionic gonadotropin (HCG) | mlU/mL | 1.0 | IU/L |
| Hydroxybutyric acid | mg/dL | 96.05 | µmol/L |
| Hydroxyproline | mg/dL | 76.3 | µmol/L |
| Immunoglobulin A (IgA) | mg/dL | 0.01 | g/L |
| Immunoglobulin D (IgD) | mg/dL | 10 | mg/L |
| Immunoglobulin E (IgE) | mg/dL | 10 | mg/L |
| Immunoglobulin G (IgG) | mg/dL | 0.01 | g/L |
| Immunoglobulin M (IgM) | mg/dL | 0.01 | g/L |
| Insulin | µIU/mL | 6.945 | pmol/L |
| Iron, total (Dual report) |
µg/dL | 0.179 | µmol/L |
| Iron binding capacity, total (Dual report) |
µg/dL | 0.179 | µmol/L |
| lsoleucine | mg/dL | 76.24 | µmol/L |
| lsopropanol | mg/L | 0.0166 | mmol/L |
| Lactate (lactic acid) | mg/dL | 0.111 | mmol/L |
| Lactate dehydrogenase | units/L | 1 | U/L |
| Lactate dehydrogenase isoenzymes (LD1-LD5) |
% | 0.01 | Proportion of 1.0 |
| Lead (Dual report) |
µg/dL | 0.0483 | µmol/L |
| Leucine | mg/dL | 76.237 | µmol/L |
| Lipase | units/L | 1.0 | U/L |
| Lipids (total) | mg/dL | 0.01 | g/L |
| Lipoprotein (a) | mg/dL | 0.0357 | µmol/L |
| Lithium | mEq/L | 1.0 | mmol/L |
| Low-density lipoprotein cholesterol (LDL-C) (Dual report) |
mg/dL | 0.0259 | mmol/L |
| Luteinizing hormone (LH, leutropin) | IU/L | 1.0 | lU/L |
| Lysine | mg/dL | 68.5 | µmol/L |
| Magnesium (Dual report) |
mg/dL | 0.411 | mmol/L
|
| mEq/L | 0.50 | mmol/L | |
| Manganese | ng/mL | 18.2 | nmol/L |
| Methanol | mg/L | 0.0312 | mmol/L |
| Methemoglobin | % of total hemoglobin |
0.01 | Proportion of total hemoglobin |
| Methionine | mg/dL | 67.02 | µmol/L |
| Myoglobin | µg/L | 0.0571 | nmol/L |
| Nicotine | mg/L | 6.164 | µmol/L |
| Nitrogen, nonprotein | mg/dL | 0.714 | mmol/L |
| Norepinephrine | pg/mL | 0.00591 | nmol/L |
| Ornithine | mg/dL | 75.67 | µmol/L |
| Osmolality | mOsm/kg | 1.0 | mmoI/kg |
| Osteocalcin | µg/L | 0.171 | nmol/L |
| Oxalate | mg/L | 11.1 | µmol/L |
| Parathyroid hormone | pg/mL | 1.0 | ng/L |
| Phenobarbital | mg/L | 4.31 | µmol/L |
| Phenylalanine | mg/dL | 60.54 | µmol/L |
| Phenytoin | µg/mL | 3.96 | µmoI/L |
| Phosphorus (Dual report) |
mg/dL | 0.323 | mmol/L |
| Plasminogen | mg/dL | 0.113 | µmol/L
|
| % | 0.01 | Proportion of 1.0 |
|
| Plasminogen activator inhibitor | mIU/mL | 1.0 | IU/L |
| Platelets (thrombocytes) | ×103/µL | 1.0 | ×109/L |
| Potassium | mEq/L | 1.0 | mmoI/L |
| Pregnanediol (urine) | mg/24h | 3.12 | µmoI/d |
| Pregnanetriol (urine) | mg/24 h | 2.97 | µmol/d |
| Progesterone | ng/mL | 3.18 | nmol/L |
| Prolactin | µg/L | 43.478 | pmol |
| Proline | mg/dL | 86.86 | µmol/L |
| Prostate-specific antigen | ng/mL | 1.0 | µg/L |
| Protein, total | g/dL | 10.0 | g/L |
| Prothrombin | g/L | 13.889 | µmol/L |
| Prothrombin time (protime, PT) | s | 1.0 | s |
| Protoporphyrin, erythrocyte | µg/dL | 0.01777 | µmol/L |
| Pyruvate | mg/dL | 113.6 | µmoI/L |
| Quinidine | µg/mL | 3.08 | µmol/L |
| Red blood cell count | ×106/µL | 1.0 | ×1012/L |
| Renin | pg/mL | 0.0237 | pmol/L |
| Reticulocyte count | % of RBCs | 0.01 | Proportion of 1.0 |
| Salicylate | mg/L | 0.00724 | mmol/L |
| Serine | mg/dL | 95.2 | µmol/L |
| Serotonin (5-hydroxytryptamine) | ng/mL | 0.00568 | µmol/L |
| Sodium | mEq/L | 1.0 | mmol/L |
| Somatomedin-C (insulinlike growth factor) | ng/mL | 0.131 | nmol/L (coagulation factor II) |
| Somatostatin | pg/mL | 0.611 | pmol/L |
| Taurine | mg/dL | 79.91 | µmol/L |
| Testosterone (Dual report) |
ng/dL | 0.0347 | nmol/L |
| Theophylline | µg/mL | 5.55 | µmol/L |
| Thiocyanate | mg/L | 17.2 | µmol/L |
| Threonine | mg/dL | 83.95 | µmol/L |
| Thyroglobulin | ng/mL | 1.0 | µg/L |
| Thyrotropin (thyroid-stimulating hormone, TSH) |
mIU/L | 1.0 | mIU/L |
| Thyroxine, free (T4) (Dual report) |
ng/dL | 12.87 | pmol/L |
| Thyroxine, total (T4) (Dual report) |
µg/dL | 12.87 | nmol/L |
| Transferrin | mg/dL | 0.01 | g/L |
| Triglycerides (Dual report) |
mg/dL | 0.0113 | mmol/L |
| Triiodothyronine | |||
| Free (T3) (Dual report) |
pg/dL | 0.0154 | pmol/L |
| Resin uptake | % | 0.01
|
Proportion of 1.0 |
| Total (T3) (Dual report) |
ng/dL | 0.0154 | nmol/L |
| Troponin I (cardiac) | ng/mL | 1.0 | µg/L |
| Troponin T (cardiac) | ng/mL | 1.0 | µg/L |
| Tryptophan | mg/dL | 48.97 | µmol/L |
| Tyrosine | mg/dL | 55.19 | µmol/L |
| Urea nitrogen (Dual report) |
mg/dL | 0.357 | mmol/L |
| Uric acid | mg/dL | 59.48 | µmol/L |
| Valine | mg/dL | 85.5 | µmol/L |
| Vasoactive intestinal polypeptide |
pg/mL | 1.0 | ng/L |
| Vitamin A (retinol) | µg/dL | 0.0349 | µmoI/L |
| Vitamin B6 (pyridoxine) | ng/mL | 4.046 | nmol/L |
| Vitamin B12 (cyanocobalamin) | pg/mL | 0.738 | pmol/L |
| Vitamin C (ascorbic acid) | mg/dL | 56.78 | µmol/L |
| Vitamin D | |||
| 1,25-Dihydroxyvitamin D | pg/mL | 2.6 | pmol/L |
| 25-Hydroxyvitamin D | ng/mL | 2.496 | nmol/L |
| Vitamin E | mg/dL | 23.22 | µmoI/L |
| Vitamin K | ng/mL | 2.22 | nmol/L |
| Warfarin | µg/mL | 3.247 | µmol/L |
| White blood cell count | ×103/µL | 1.0 | ×109/L |
| White blood cell differential count (number fraction) |
% | 0.01 |
of 1.0 |
| Zinc | µg/dL | 0.153 | µmoI/L |
The information in this table is from the following sources:
Iverson C, Flanagin A, Fontanarosa PB, et al. American Medical Association Manual of Style: A Guide for Authors and Editors. 9th ed. Baltimore, Md: Williams & Wilkins; 1998.
Tietz NW, ed. Clinical Guide to Laboratory Tests. 3rd ed. Philadelphia, Pa: WB Saunders Co; 1995.
Jacobs DS, Demott WR, Grady HJ, et al, eds. Laboratory Test Handbook. 4th ed. Hudson, Ohio: Lexi-Comp Inc; 1996.
Young DS, Huth EJ. SI Units for Clinical Measurement. Philadelphia, Pa: American College of Physicians; 1998.
Kratz A, Lewandrowski KB. Normal reference laboratory values. N Engl J Med. 1998;339:1036-1042.
Dual Report
Because of the continued use of conventional units in many laboratories in the United States, some of the more common analytes currently are dual reported (identified as "Dual report" in this table), with the SI value and unit listed first, followed by the conventional value and unit. Analytes with a 1-to-1 conversion between SI and conventional units or with a conversion factor that is a multiple of 10 usually are not dual reported. Information on how to convert from SI units to conventional units may be given in the text, in a table footnote, or in a figure legend (eg, to convert ethanol from millimoles per liter to milligrams per deciliter, divide millimoles per liter by 0.217).
