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Lab Test Reference Range Lookup

The short answer

Pick a blood test and, if it matters for that marker, your sex and age, and this tool shows the typical adult reference range major US labs use, in the lab's units. Ranges come from TestWell's reference catalog of 130+ biomarkers, each with a cited source. Your own report's printed range always takes precedence.

Markers
130+
Filters
Sex · age · pregnancy
Source
Cited catalog
Cost
Free

TSH reference range

Units: mIU/L / uIU/mL

A pituitary hormone that signals your thyroid. The most sensitive screen for thyroid problems.

PopulationRange
age 18+0.450 – 4.50 mIU/L

Higher than range

Often reflects an underactive thyroid (hypothyroidism); medications and recovery from illness can also raise TSH.

Lower than range

Often reflects an overactive thyroid (hyperthyroidism), excess thyroid medication, or pituitary issues.

Full TSH guide, sources and how to order →

Educational. Interpret your result against the range printed on your own lab report; ranges differ slightly between labs.

What is a reference range, and how is it set?

A reference range (or reference interval) is the span of values a lab expects in healthy people, usually the central 95% of results from a reference population. That construction has two consequences worth knowing: about 1 in 20 healthy results falls just outside the range by design, and ranges differ between labs because each lab validates its own analyzers and population. Some markers also change with sex, age, pregnancy or menopause, which is why this tool lets you filter — and why your report's printed range is the one to use.

Which markers are covered?

All 131markers in TestWell's reference catalog, with the default adult band shown here. Sex- and age-specific bands appear in the tool above and on each marker's page.

Blood Health

MarkerTypical range
Basophils0.000 – 2.00 %
Eosinophils1.00 – 4.00 %
Haptoglobin30.0 – 200 mg/dL
Hematocrit38.8 – 50.0 %
Hemoglobin13.5 – 17.5 g/dL
Lymphocytes20.0 – 40.0 %
MCH27.0 – 33.0 pg
MCHC32.0 – 36.0 g/dL
MCV80.0 – 100 fL
Monocytes2.00 – 8.00 %
MPV7.50 – 11.5 fL
Neutrophils40.0 – 70.0 %
Platelet Count150 – 450 10^3/uL
RDW11.5 – 14.5 %
Red Blood Cell Count4.70 – 6.10 10^6/uL
Reticulocyte %0.500 – 2.50 %
Reticulocyte Count30.0 – 100 10^9/L
White Blood Cell Count4.50 – 11.0 10^3/uL

Diabetes & Blood Sugar

MarkerTypical range
C-Peptide1.10 – 4.40 ng/mL
Fasting Insulin2.00 – 20.0 uIU/mL
Hemoglobin A1c4.00 – 5.60 %

Heart Health

MarkerTypical range
AFP0.000 – 8.50 ng/mL
Apolipoprotein B0.000 – 90.0 mg/dL
CA 19-90.000 – 37.0 U/mL
CA-1250.000 – 35.0 U/mL
CEA0.000 – 3.00 ng/mL
DHA30.0 – 250 mcg/mL
EPA14.0 – 100 mcg/mL
Free PSA %25.0 – 100 %
HDL Cholesterol40.0 – 100 mg/dL
HDL Particle Number30.5 – 50.0 umol/L
Homocysteine4.00 – 10.0 umol/L
LDL Cholesterol0.000 – 100 mg/dL
LDL Particle Number0.000 – 1000 nmol/L
LDL Particle Size20.6 – 22.0 nm
LDL/HDL Ratio0.000 – 3.50 ratio
Lipoprotein(a)0.000 – 75.0 nmol/L
Non-HDL Cholesterol0.000 – 130 mg/dL
NT-proBNP0.000 – 125 pg/mL
Omega-3 Index8.00 – 12.0 %
PSA Total0.000 – 2.50 ng/mL
Small LDL Particle0.000 – 527 nmol/L
Total Cholesterol125 – 200 mg/dL
Triglycerides0.000 – 150 mg/dL
VLDL Cholesterol5.00 – 30.0 mg/dL

Hormones

MarkerTypical range
Adiponectin4.00 – 20.0 mcg/mL
Aldosterone0.000 – 30.0 ng/dL
AMH1.00 – 6.80 ng/mL
Cortisol AM6.20 – 19.4 mcg/dL
Cortisol PM2.30 – 11.9 mcg/dL
DHEA-S160 – 449 mcg/dL
Dihydrotestosterone (DHT)30.0 – 85.0 ng/dL
Estradiol10.0 – 40.0 pg/mL
Free Testosterone47.0 – 244 pg/mL
FSH1.50 – 12.4 mIU/mL
IGF-1116 – 358 ng/mL
Leptin0.500 – 12.5 ng/mL
LH1.70 – 8.60 mIU/mL
Progesterone0.100 – 0.500 ng/mL
Prolactin4.00 – 15.2 ng/mL
PTH, Intact15.0 – 65.0 pg/mL
SHBG16.5 – 55.9 nmol/L
Total Testosterone264 – 916 ng/dL

Inflammation & Autoimmune

MarkerTypical range
C-Reactive Protein0.000 – 10.0 mg/L
ESR0.000 – 15.0 mm/hr
hs-CRP0.000 – 3.00 mg/L
Rheumatoid Factor0.000 – 14.0 IU/mL
Total IgA70.0 – 400 mg/dL
Tryptase0.000 – 11.5 ng/mL
tTG-IgA0.000 – 4.00 U/mL

Iron & Anemia

MarkerTypical range
Ferritin24.0 – 336 ng/mL
Iron65.0 – 175 mcg/dL
Iron Saturation20.0 – 50.0 %
TIBC250 – 450 mcg/dL
Transferrin200 – 360 mg/dL

Metabolic Health

MarkerTypical range
Activated Partial Thromboplastin Time (aPTT)25.0 – 35.0 seconds
Albumin3.50 – 5.00 g/dL
Albumin/Creatinine Ratio0.000 – 30.0 mg/g
Alkaline Phosphatase40.0 – 129 U/L
ALT7.00 – 55.0 U/L
Amylase26.0 – 102 U/L
AST8.00 – 48.0 U/L
Bilirubin0.100 – 1.20 mg/dL
BUN7.00 – 20.0 mg/dL
Calcium8.60 – 10.3 mg/dL
Carbon Dioxide22.0 – 29.0 mmol/L
Chloride98.0 – 107 mmol/L
Copper70.0 – 140 mcg/dL
Creatine Kinase39.0 – 308 U/L
Creatinine0.740 – 1.35 mg/dL
Cystatin C0.550 – 1.00 mg/L
D-Dimer0.000 – 500 ng/mL
Direct Bilirubin0.000 – 0.300 mg/dL
eGFR60.0 – 120 mL/min/1.73m2
eGFR (Cystatin C)60.0 – 120 mL/min/1.73m2
Fibrinogen200 – 400 mg/dL
GGT8.00 – 61.0 U/L
Glucose70.0 – 99.0 mg/dL
INR0.800 – 1.10 ratio
LDH122 – 222 U/L
Lead (Blood)0.000 – 3.50 mcg/dL
Lipase13.0 – 60.0 U/L
Magnesium1.70 – 2.20 mg/dL
Mercury (Blood)0.000 – 10.0 mcg/L
Phosphorus2.50 – 4.50 mg/dL
Potassium3.50 – 5.00 mmol/L
Prealbumin18.0 – 40.0 mg/dL
Prothrombin Time11.0 – 13.5 seconds
Selenium70.0 – 150 mcg/L
Sodium135 – 145 mmol/L
Total Protein6.30 – 8.30 g/dL
Uric Acid3.40 – 7.00 mg/dL
Urine Albumin0.000 – 30.0 mg/g
Urine Creatinine20.0 – 320 mg/dL
Zinc60.0 – 130 mcg/dL

Thyroid

MarkerTypical range
Free T32.00 – 4.40 pg/mL
Free T40.820 – 1.77 ng/dL
Reverse T38.00 – 25.0 ng/dL
Thyroglobulin Antibodies0.000 – 4.00 IU/mL
TPO Antibodies0.000 – 35.0 IU/mL
TSH0.450 – 4.50 mIU/L

Vitamins & Nutrients

MarkerTypical range
Folate3.40 – 25.0 ng/mL
Vitamin A (Retinol)38.0 – 98.0 mcg/dL
Vitamin B1 (Thiamine)70.0 – 180 nmol/L
Vitamin B12200 – 1100 pg/mL
Vitamin B2 (Riboflavin)137 – 370 nmol/L
Vitamin B620.0 – 125 nmol/L
Vitamin C0.400 – 2.00 mg/dL
Vitamin D, 25-Hydroxy30.0 – 100 ng/mL
Vitamin E5.50 – 17.0 mg/L
Vitamin K10.100 – 2.20 ng/mL

Frequently asked questions

Which tests give you these numbers?

Physician-authorized, drawn at Quest, Labcorp or BioReference. Results in 1–3 business days for most tests.