Reference ranges for commonly used tests.1,2  

Modified from Nicoll D et al: Pocket Guide to Diagnostic Tests, 4th ed. McGraw-Hill, 2004.

Current metric units x Conversion factor = SI units
SI units ÷ Conversion factor = Current metric units
Test Specimen Conventional Units Conversion Factor SI Units2
 		 Collection3
 
Acetaminophen Serum
10–20 mg/L
Panic: > 50 mg/L
 66.16 66–132 mcmol/L Serum separator tube (SST)
Acetoacetate Serum or urine Negative   Negative SST or urine container
Adrenocorticotropic hormone (ACTH) Plasma 9–52 pg/mL (laboratory-specific) 0.22 2–11 pmol/L Siliconized glass or plastic lavender
Alanine aminotransferase (ALT, SGPT, GPT) Serum 7–56 units/L (laboratory-specific) 0.02 0.14–1.12 mckat/L (laboratory-specific) SST
Albumin Serum 3.4–4.7 g/dL 10.00 34–47 g/L SST
Aldosterone Serum Salt-loaded (120 mEq Na+/d):
 		 27.74   SST
  Supine: 3–10 ng/dL 83–277 pmol/L
  Upright: 5–30 ng/dL 139–831 pmol/L
Salt-depleted (20 mEq Na+/d):
 		  
  Supine: 12–36 ng/dL 332–997 pmol/L
  Upright: 17–137 ng/dL 471–3795 pmol/L
Urine Salt-loaded (120 mEq Na+/d for 3–4 days): 1.5–12.5 mcg/24 h
 		 2.77 4.2–34.6 nmol/d Boric acid
Salt-depleted (20 mEq Na+/d for 3–4 days): 18–85 mcg/24 h
 		 49.9–235.5 nmol/d
Alkaline phosphatase Serum 41–133 units/L (method- and age-dependent) 0.02 0.7–2.2 mckat/L (method- and age-dependent) SST
Ammonia (NH3)
 		 Plasma 18–60 mcg/dL 0.59 11–35 mcmol/L Green (iced)
Amylase Serum 20–110 units/L (laboratory-specific) 0.02 0.33–1.83 mckat/L (laboratory-specific) SST
Angiotensin-converting enzyme (ACE) Serum 12–35 units/L (method-dependent) 16.67 < 590 nkat/L (method-dependent) SST
Antithrombin III (AT III) Plasma
84–123% (qualitative)
22–39 mg/dL (quantitative)
     Blue
1-Antitrypsin
 		 Serum 110–270 mg/dL 0.01 1.1–2.7 g/L SST
Aspartate aminotransferase (AST, SGOT, GOT) Serum 0–35 units/L (laboratory-specific) 0.02 0–0.58 mckat/L (laboratory-specific) SST
Basophil count Whole blood 0.01–0.12 x 103/mcL
 		 1.00 0.01–0.12 x 109/L
 		 Lavender
Bilirubin Serum
Total: 0.1–1.2 mg/dL
Direct (conjugated to glucuronide): 0.1–0.5 mg/dL
Indirect (unconjugated): 0.1–0.7 mg/dL
 17.10
2–21 mcmol/L
< 8 mcmol/L
< 12 mcmol/L
 SST
Blood urea nitrogen (BUN) Serum 8–20 mg/dL 0.36 2.9–7.1 mmol/L SST
-Natriuretic peptide Whole blood < 50 pg/mL     Lavender
C-peptide Serum 0.8–4.0 ng/mL 1.00 0.8–4.0 mcg/L
Iced (fasting)
Gold SST
C-reactive protein Serum <5 mg/L 1.00 <5 mg/L SST
Calcitonin Plasma
Male: 0–11.5 pg/mL
Female: 0–4.6 pg/mL
 1.00
Male: 0–11.5 ng/L
Female: 0–4.6 ng/L
Green
Gold SST
Calcium (Ca2+)
 		 Serum
8.5–10.5 mg/dL
Panic: < 6.5 or > 13.5 mg/dL
 0.25 2.1–2.6 mmol/L SST
Calcium (ionized) Serum 4.6–5.3 mg/dL 0.25 1.15–1.32 mmol/L Green (anaerobic)
Calcium (UCa)
 		 Urine 100–300 mg/d 0.025 2.5–7.5 mmol/d Urine bottle containing hydrochloric acid
Carbon dioxide, partial pressure (Pco2)
 		 Whole blood 32–48 mm Hg 0.13 4.26–6.38 kPa Heparinized syringe (iced)
Carbon dioxide (CO2), total (bicarbonate)
 		 Serum
22–32 mEq/L
Panic: < 15 or > 40 mEq/L
 1.00
22–32 mmol/L
Panic: < 15 or > 40 mmol/L
 SST
Carboxyhemoglobin (HbCO) Whole blood < 9% of total hemoglobin (Hb) 0.01 < 0.09 fraction of total hemoglobin Green
Carcinoembryonic antigen (CEA) Serum 0–5 ng/mL 1.00 0–5 mcg/L SST
CD4 T cell count Whole blood 359–1725 cells/mcL     Lavender (complete blood count and differential and % CD4 required)
Ceruloplasmin Serum 20–60 mg/dL (laboratory-specific) 10.00 200–600 mg/L SST
Chloride (Cl–)
 		 Serum 101–112 mEq/L 1.00 101–112 mmol/L SST
Cholesterol Serum
Desirable: < 200 mg/dL
Borderline: 200–239 mg/dL
High risk: > 240 mg/dL
 0.03
Desirable: < 5.2 mmol/L
Borderline: 5.2–6.1 mmol/L
High risk: > 6.2 mmol/L
 SST
Chorionic gonadotropin, -subunit (-hCG), quantitative Serum Males and nonpregnant females: undetectable or < 5 mU/mL 1.00 Males and nonpregnant females: undetectable or < 5 units/L SST
Complement C3 Serum 64–166 mg/dL 10.00 640–1660 mg/L SST
Complement C4 Serum 15–45 mg/dL 10.00 150–450 mg/L SST
Complement CH50 Serum (Laboratory-specific)     Red
Cortisol Serum 8:00 AM: 5–20 mcg/dL  27.59 140–550 nmol/L SST
Cortisol (urinary free) Urine 10–110 mcg/24 h 2.76 30–300 nmol/d Urine bottle containing boric acid
Creatine kinase (CK) Serum 32–267 units/L (method-dependent) 0.02 0.53–4.45 mckat/L (method-dependent) SST
Creatine kinase MB (CKMB) Serum
< 16 units/L or < 4% of total CK (laboratory-specific)
Mass units: 0–7 mcg/L
 0.04 < 0.27 mckat/L SST
Creatinine (Cr) Serum 0.6–1.2 mg/dL 83.3 50–100 mcmol/L SST
Creatinine clearance (ClCr)
 		 See Collection column. Adults: 90–140 mL/min/1.73 m2 body surface area (BSA)
 		 0.017 1.5–2.3 mL/s/1.73 m2 BSA
 		 Carefully timed 24-hour urine and simultaneous serum or plasma creatinine sample
Cryoglobulins Serum < 0.12 mg/dL     Red (at 37°C)
Eosinophil count Whole blood 0.04–0.5 x 103/mcL
 		 1.00 0.04–0.5 x 109/L
 		 Lavender
Erythrocyte count (RBC count) Whole blood 4.7–6.1 x 106/mcL
 		 1.00 4.7–6.1 x 1012/L
 		 Lavender
Erythrocyte sedimentation rate Whole blood
Male: < 10 mm/h
Female: < 15 mm/h (laboratory-specific)
   Same Lavender
Erythropoietin (EPO) Serum 5–20 mU/mL 1.00 5–20 units/L SST
Ethanol Serum
mg/dL
Legal "driving under the influence" in many states is defined as > 80 mg/dL (> 17 mmol/L) blood alcohol level; serum alcohol levels are 10–35% higher than blood alcohol levels
 0.217 mmol/L SST
Factor VIII assay Plasma 40–150% of normal (varies with age)     Blue
Fecal fat Stool
Random: < 60 droplets of fat per high-power field
72-hour: < 7 g/d
    
Qualitative: Random stool sample
Quantitative: 72-hour collection following 2-day dietary fat regimen
Ferritin Serum
Male: 16–300 ng/mL
Female: 4–161 ng/mL
 1.00
Male: 16–300 mcg/L
Female: 4–161 mcg/L
 SST
-Fetoprotein (AFP) Serum 0–15 ng/mL 1.00 0–15 mcg/L SST
Fibrin D-dimers  Plasma Negative     Blue
Fibrinogen (functional) Plasma
175–433 mg/dL
Panic: < 75 mg/dL
 0.01 1.75–4.3 g/L Blue
Folic acid (red cells) Whole blood 165–760 ng/mL 2.27 370–1720 nmol/L Lavender
Follicle-stimulating hormone (FSH) Serum Female: 1.00 Female: SST
Follicular phase 4–13 mU/mL 4–13 units/L
Luteal phase 2–13 mU/mL 2–13 units/L
Midcycle 5–22 mU/mL 5–22 units/L
Postmenopausal 30–138 mU/mL 30–138 units/L
Male: 1–10 mU/mL (laboratory-specific) Male: 1–10 units/L (laboratory-specific)
Free erythrocyte protoporphyrin (FEP) Whole blood < 35 mcg/dL (method-dependent)     Lavender
Fructosamine Serum     190–270 mcmol/L SST
-Glutamyltranspeptidase (GGT) Serum 9–85 units/L (laboratory-specific) 0.02 0.15–1.42 mckat/L (laboratory-specific) SST
Gastrin Serum < 100 pg/mL (laboratory-specific) 1.00 < 100 ng/L SST
Glucose Serum
60–110 mg/dL
Panic: < 40 or > 500 mg/dL
 0.055 3.3–6.1 mmol/L
(Fasting)
SST
Glucose-6-phosphate dehydrogenase (G6PD) screen Whole blood 5–14 units/g Hb 0.02 0.1–0.28 mckat/L Lavender
Glutamine Cerebrospinal fluid (CSF)
6–15 mg/dL
Panic: > 40 mg/dL
 68.5 411–1028 mcmol/L Collect CSF in a plastic tube
Glycated (glycosylated) hemoglobin (HbA1c)
 		 Serum 3.9–6.9% (method- dependent)     Lavender
Growth hormone (GH) Serum 0–5 ng/mL 1.00 0–5 mcg/L SST
Haptoglobin Serum 46–316 mg/dL 0.01 0.5–3.2 g/L SST
HDL cholesterol Serum
Male: 27–67 mg/dL
Female: 34–88 mg/dL
 0.026
0.7–1.73 mmol/L
0.88–2.28 mmol/L
 SST
Helicobacter pylori antibody  Serum Negative     SST
Hematocrit (Hct) Whole blood
Male: 39–49%
Female: 35–45% (age-dependent)
 0.01
Male: 0.39–0.49
Female: 0.35–0.45
 Lavender
Hemoglobin A1c (See Glycated Hemoglobin)
 		 Serum        
Hemoglobin A2 (HbA2)
 		 Whole blood 1.5–3.5% of total hemoglobin 0.01 0.015–0.035 Lavender
Hemoglobin electrophoresis Whole blood
HbA: > 95%
HbA2: 1.5–3.5%
     Lavender
Hemoglobin, fetal (HbF) Whole blood Adult: < 2% (varies with age)     Lavender
Hemoglobin, total (Hb) Whole blood
Male: 13.6–17.5 g/dL
Female: 12.0–15.5 g/dL
Panic: 7 g/dL (age-dependent)
 10.00
Male: 136–175 g/L
Female: 120–155 g/L
 Lavender
Hemosiderin Urine Negative     Urine container
HIV viral load Plasma Negative     Lavender
Homocysteine Plasma 4–12 mcmol/L 1.00 4–12 mcmol/L Lavender
5-Hydroxyindoleacetic acid (5-HIAA) Urine 2–8 mg/24 h 5.23 10–40 mcmol/d Urine bottle containing hydrochloric acid
IgG index Serum and CSF 0.29–0.59 ratio     SST and plastic tube for CSF
Immunoglobulins (Ig) Serum
IgA: 78–367 mg/dL
IgG: 583–1761 mg/dL
IgM: 52–335 mg/dL
 0.01
IgA: 0.78–3.67 g/L
IgG: 5.83–17.6 g/L
IgM: 0.52–3.35 g/L
 SST
Insulin, immunoreactive Serum 6–35 mcU/mL 7.18 42–243 pmol/L SST
Insulin-like growth factor-1 Plasma 123–463 ng/mL (age- and sex-dependent) 1.0 123–463 mcg/L SST
Iron (Fe2+)
 		 Serum 50–175 mcg/dL 0.18 9–31 mcmol/L SST
Iron-binding capacity, total (TIBC) Serum 250–460 mcg/dL 0.18 45–82 mcmol/L SST
Lactate dehydrogenase (LDH) Serum 88–230 units/L (laboratory-specific) 0.02 1.46–3.82 mckat/L (laboratory-specific) SST
Lactic acid (lactate) Venous blood 0.5–2.0 mEq/L 1.00 0.5–2.0 mmol/L Gray
LDL cholesterol Serum < 130 mg/dL 0.026 < 3.37 mmol/L SST
Lead (Pb) Whole blood
Child: < 25 mcg/dL
Adult: < 40 mcg/dL
 0.05
Child: < 1.21 mcmol/L
Adult: < 1.93 mcmol/L
 Navy
Lecithin/sphingomyelin (L/S) ratio Amniotic fluid > 2.0 (method-dependent)     Collect in a plastic tube
Leukocyte alkaline phosphatase (LAP) Whole blood
40–130
Based on 0 to 4+ rating of 100 polymorphonuclear neutrophils stained for alkaline phosphatase
     Green
Leukocyte (white blood cell) count, total (WBC count) Whole blood
4.8–10.8 x 103/mcL
Panic: < 1.5 x 103/mcL
 1.00 4.8–10.8 x 109/L
 		 Lavender
Lipase Serum 0–160 units/L (laboratory-specific) 0.02 0–2.66 mckat/L (laboratory-specific) SST
Luteinizing hormone (LH) Serum Female: 1.00   SST
  Follicular phase 1–18 mU/mL 1–18 units/L
  Luteal phase 0.4–20 mU/mL 0.4–20 units/L
  Midcycle 24–105 mU/mL 24–105 units/L
  Postmenopausal 15–62 mU/mL 15–62 units/L
Male: 1–10 mU/mL (laboratory-specific) Male: 1–10 units/L (laboratory-specific)
Lymphocyte count Whole blood 0.8–3.5 x 103/mcL
 		 1.00 0.8–3.5 x 109/L
 		 Lavender
Magnesium (Mg2+)
 		 Serum
1.8–3.0 mg/dL
Panic: < 0.5 or > 4.5 mg/dL
 0.41 0.75–1.25 mmol/L SST
Mean corpuscular hemoglobin (MCH) Whole blood 26–34 pg     Lavender
Mean corpuscular hemoglobin concentration (MCHC) Whole blood 31–36 g/dL 10.00 310–360 g/L Lavender
Mean corpuscular volume (MCV) Whole blood 80–100 fL     Lavender
Metanephrines Urine 0.3–0.9 mg/24 h 5.46 1.6–4.9 mcmol/d Urine bottle containing hydrochloric acid
Methemoglobin (MetHb) Whole blood < 1% of total hemoglobin 0.01 < 0.01 fraction of total hemoglobin Green
Methylmalonic acid Serum 0–0.05 mg/L 8.475 0–0.4 mcmol/L SST
Monocyte count Whole blood 0.2–0.8 x 103/mcL
 		 1.00 0.2–0.8 x 109/L
 		 Lavender
Neutrophil count Whole blood 2.2–8.6 x 103/mcL
 		 1.00 2.2–8.6 x 109/L
 		 Lavender
Osmolality Serum
275–293 mosm/kg H2O
Panic: < 240 or > 320 mosm/kg H2O
 1.00 275–293 mmol/kg H2O
 		 SST
Urine Random: 100–900 mosm/kg H2O
 		 1.00 Random: 100–900 mmol/kg H2O
 		 Urine container
Oxygen, partial pressure (Po2)
 		 Whole blood 83–108 mm Hg 0.13 11.04–14.36 kPa Heparinized syringe (iced)
Parathyroid hormone (PTH) Serum Intact PTH: 11–54 pg/mL (laboratory-specific) 0.11 Intact PTH: 1.2–5.7 pmol/L (laboratory-specific) Red
Partial thromboplastin time, activated (PTT) Plasma
25–35 seconds (range varies)
Panic: 60 seconds
     Blue
pH Whole blood
Arterial: 7.35–7.45
Venous: 7.31–7.41
     Heparinized syringe (iced)
Phosphorus Serum
2.5–4.5 mg/dL
Panic: < 1.0 mg/dL
 0.32 0.8–1.45 mmol/L SST
Platelet count (Plt) Whole blood
150–450 x 103/mcL
Panic: < 25 x 103/mcL
 1.0
150–450 x 109/L
Panic: < 25 x 109/L
 Lavender
Platelet-associated IgG Whole blood Negative     Lavender
Porphobilinogen (PBG) Urine Negative     Protect from light
Potassium (K+)
 		 Serum
3.5–5.0 mEq/L
Panic: < 3.0 or > 6.0 mEq/L
 1.00 3.5–5.0 mmol/L SST
Prolactin (PRL) Serum < 20 ng/mL 1.00 < 20 mcg/L SST
Prostate-specific antigen (PSA) Serum 0–4 ng/mL 1.00 0–4 mcg/L SST
Protein C Plasma 71–176%     Blue
Protein electrophoresis Serum
Adults:
Albumin: 3.3–4.7 g/dL
1: 0.1–0.4 g/dL
2: 0.3–0.9 g/dL
2: 0.7–1.5 g/dL
: 0.5–1.4 g/dL
 10.00
33–47 g/L
1–4 g/L
3–9 g/L
7–15 g/L
5–14 g/L
 SST
Protein S (antigen) Plasma 76–178%     Blue
Protein, total Serum 6.0–8.0 g/dL 10.00 60–80 g/L SST
Prothrombin time (PT) Whole blood
11–15 seconds
Panic: 30 seconds (laboratory-specific)
     Blue
Red blood cell count Whole blood 4.7–6.1 x 106/mcL
 		 1.00 4.7–6.1 x 1012/L
 		 Lavender
Red cell volume Whole blood 25–35 mL/kg     Green
Renin activity (PRA) Plasma
High-sodium diet (75–150 mEq Na+/d):
Supine: 0.2–2.3 ng/mL/h
Standing: 1.3–4.0 ng/mL/h)
Low-sodium diet (30–75 mEq Na+/d):
Standing: 4.0–7.7 ng/mL/h)
     Lavender
Reptilase clotting time Plasma 13–19 seconds     Blue
Reticulocyte count Whole blood 33–137 x 103/mcL
 		 1.00 33–137 x 109/L
 		 Lavender
Russell's viper venom clotting time (dilute) (RVVT) Plasma 24–37 seconds     Blue
Salicylate (aspirin, others) Serum
20–30 mg/dL
Panic: > 35 mg/dL
 10.00 200–300 mg/L SST
Sodium (Na+)
 		 Serum
135–145 mEq/L
Panic: < 125 or > 155 mEq/L
 1.00 135–145 mmol/L SST
Testosterone Serum
Male: 175–781 ng/dL
Female: 10–75 ng/dL
 0.0347
Male: 6–27 nmol/L
Female: 0.3–2.6 nmol/L
 SST
Thrombin time Plasma 8–12 seconds (laboratory-specific)     Blue
Thyroglobulin Serum 3–42 ng/mL 1.00 3–42 mcg/L SST
Thyroid-stimulating hormone (TSH) Serum 0.4–6 mcU/mL 1.00 0.4–6 mU/L SST
Thyroid-stimulating hormone receptor antibody (TSH-R Ab [stim]) Serum < 130% of basal activity; based on cAMP generation in thyroid cell tissue culture      
Thyroxine, free (FT4)
 		 Serum 9–24 pmol/L (varies with method)     SST
Thyroxine (T4), total
 		 Serum 5–11 mcg/dL 12.80 64–142 nmol/L SST
Thyroxine index, free (FT4I)
 		 Serum 6.5–12.5     SST
Transferrin Serum 190–375 mg/dL 0.01 1.9–3.75 g/L SST
Triglycerides Serum < 165 mg/dL 0.01 < 1.8 mmol/L SST (fasting)
Triiodothyronine (T3), total
 		 Serum 95–190 ng/dL 0.015 1.5–2.9 nmol/L SST
Troponin-I (cTnI) Serum < 0.05 ng/mL     SST
Uric acid Serum
Male: 2.4–7.4 mg/dL
Female: 1.4–5.8 mg/dL
 59.48
Male: 140–440 mcmol/L
Female: 80–350 mcmol/L
 SST
Vanillylmandelic acid (VMA) Urine 2–7 mg/24 h 5.05 10–35 mcmol/d Urine bottle containing hydrochloric acid
Vitamin B12
 		 Serum 140–820 pg/mL 0.74 100–600 pmol/L SST
Vitamin B12 absorption test (Schilling test)
 		 24-hour urine Excretion of > 8% of administered dose     Urine bottle
Vitamin D, 25-hydroxy (25[OH]D) Serum 10–50 ng/mL 2.5 25–125 nmol/L SST
Vitamin D, 1,25-dihydroxy (1,25[OH]2D)
 		 Serum 20–76 pg/mL 2.4 48–182 pmol/L SST
White blood cell count Whole blood 4.8–10.8 x 103/mcL
 		 1.00 4.8–10.8 x 109/L
 		 Lavender

1The reference ranges given here in conventional units and in SI units are from several large medical centers. Always use the reference ranges provided by your clinical laboratory, since ranges may be method dependent.

2Reference: Young DS: Implementation of SI units for clinical laboratory data. Ann Intern Med 1987;106:114; JAMA Instructions for Authors, JAMA 1997;278:74.

3SST = serum separator tube.