Cortisol Levels Chart: Normal Ranges, Age & Time of Day
Understand cortisol reference ranges, sample timing, age and testing method. Compare source-specific examples and learn why your lab report matters.
Updated September 16, 2026 · By Cortisol+ Editorial
What is a normal cortisol level?
A cortisol result needs a sample type, collection time, unit and laboratory reference interval. A generic online chart cannot classify every person's result. Cortisol changes through the day, and a serum result cannot be compared directly with a saliva or urine result.
Cortisol levels chart: blood-test reference ranges
These are examples from named sources, not interchangeable diagnostic cutoffs. Use the reference interval on your own report.
| Source and group | Timing | Range |
|---|---|---|
| Mayo Clinic Laboratories CORT, adults 18+ | a.m. | 7–25 mcg/dL |
| Mayo CORT, adults 18+ | p.m. | 2–14 mcg/dL |
| MedlinePlus blood-test example | 8 a.m. | 5–25 mcg/dL (138–690 nmol/L) |
The difference between these examples shows why “normal cortisol” is not one universal number. Tests performed after a suppression or stimulation medicine have their own interpretation.
Normal cortisol levels by age
Mayo's CORT assay lists separate pediatric intervals and an adult category beginning at 18. It does not provide a different target for every adult decade. Do not invent a goal for your 30s, 40s or 60s by extrapolating a social-media chart. For a child's result, use the age-specific interval from the testing laboratory and the child's clinician.
Time of day and the daily curve
Blood cortisol generally follows a daily rhythm, with higher morning and lower late-evening levels. A single sample is one observation, not a complete day of hormone output. Record when the sample was collected and follow the instructions for that test.
What are normal cortisol levels in women?
There is no single cortisol number that is normal for every woman. The Mayo CORT serum assay uses the adult morning and afternoon intervals shown above rather than a separate female range. Pregnancy, estrogen medication, collection time and the laboratory method matter when interpreting a result.
Pregnancy and estrogen-containing medication can affect total serum cortisol and its binding proteins. Mayo's assay documentation describes these and other interpretation cautions. An online gender-based correction is not a substitute for that context. Tell your clinician what medicines and supplements you use; do not stop prescribed medication to change a result without medical guidance.
Saliva and urine are different measurements
In a clinical evaluation, the question determines the test. NIDDK describes late-night salivary cortisol, 24-hour urinary free cortisol and dexamethasone suppression testing among the approaches used when Cushing's syndrome is suspected. A four-point wellness panel is not automatically the right next step for nonspecific fatigue.
What to do with an unexpected result
- Check the sample type, units, collection time and printed reference interval.
- Ask the ordering clinician how your symptoms, medication and test protocol affect interpretation.
- Ask whether follow-up testing is needed. A reference-range flag is not a diagnosis by itself.
Can Cortisol+ tell me whether my level is normal?
No. Cortisol+ displays wearable stress and recovery signals and a wellness score. It cannot determine whether blood, saliva or urine cortisol is normal. A 0–100 app score must never be substituted into a laboratory chart.
Read our methodology and limitations, Apple Watch guide and testing guide.
Correction, September 9, 2026: replaced unsourced universal ranges and fixed percentage claims with source-specific examples and clearer test limitations. This is an editorial update, not a clinical review.