Testosterone: what is a good level?

Written by Steve Fayzulayev. Clinically reviewed by Naomi Fayzulayev, FNP-C, MSN.

Last reviewed 2026-11-09. See our editorial policy and methodology.

Reference intervals depend on the laboratory, assay and population. One harmonised interval of 264–916 ng/dL was derived from healthy nonobese men aged 19–39; it is not a universal diagnostic or treatment range.

Longevity-optimised target 600–900 ng/dL total (men), 15–70 ng/dL (women)

This is the range used by the hormonal dial in the Longevity Score calculator. It is deliberately tighter than the range printed on a standard lab report — the reasoning is below.

What your lab flags vs what the evidence supportsng/dL
Standard
264–916
Optimised
600–900 ng/dL total (men), 15–70 ng/dL (women)
2006001000

Nothing you type here is sent anywhere, stored, or logged. It never leaves this page.

A result anywhere in the pale band is reported as normal and generates no comment. The brighter band is where risk is lowest. The distance between them is the part a standard report does not tell you.

What Testosterone actually measures

Testosterone is the principal androgen in both sexes, produced mainly in the testes in men and in the ovaries and adrenal glands in women. It acts on muscle, bone, brain, marrow and metabolic tissue.

Total testosterone includes testosterone bound to SHBG and albumin as well as the unbound fraction. SHBG can affect interpretation; whether free testosterone testing is useful depends on symptoms, the assay and clinical context.

Why it matters

In men, low testosterone can occur alongside changes in sexual function, muscle and bone, but these findings have many possible causes. Symptoms and consistently low levels both matter when evaluating hypogonadism.

Testosterone has roles in women as well as men. Elevated levels in women can have several causes, including polycystic ovary syndrome, and require clinical interpretation.

Illness, sleep, medications and other factors can affect a result. A single measurement does not establish the cause of a low value.

Why it's on the dashboard

The hormonal dial includes total testosterone as one part of a broader picture. In older men with low testosterone, Snyder et al. (New England Journal of Medicine, 2016) found improvements in sexual function with treatment, but the primary walking outcome did not significantly improve in the physical-function trial. These findings do not make a calculator result a diagnosis or justify treatment without clinical evaluation. See the Hormonal dial for the broader context.

Why this range is stricter than your lab's

Reference intervals describe a selected reference population and depend on the assay. They are not interchangeable with diagnostic criteria or individual treatment goals.

The calculator's range is a model choice, not a diagnosis or treatment target. Clinical interpretation depends on symptoms, repeat measurements and the laboratory method.

This distinction applies across the whole panel, not just this marker — see optimal versus standard lab ranges for the general case.

What moves Testosterone

Sleep and health
Sleep, illness and overall health can affect testosterone measurements.
Medication review
Some medicines affect hormone levels. Discuss changes with the prescribing clinician.
Testosterone therapy
For appropriately diagnosed patients, treatment is a clinical decision with fertility, haematocrit and other considerations. Never start or change it based on a calculator score.

Educational information, not a treatment plan. Discuss changes to medication or supplementation with a clinician who knows your history.

How fast it responds

Levels vary during the day and between measurements. Ask your clinician whether and when repeat testing is appropriate. See response times across all markers for how this compares.

What can distort the result

Score Testosterone against all 8 dials

Frequently asked questions

What is a good Testosterone level?

The longevity-optimised target used in this calculator is 600–900 ng/dL total (men), 15–70 ng/dL (women). Reference intervals depend on the laboratory, assay and population. One harmonised interval of 264–916 ng/dL was derived from healthy nonobese men aged 19–39; it is not a universal diagnostic or treatment range.

Why is this target stricter than the range on my lab report?

Reference intervals describe a selected reference population and depend on the assay. They are not interchangeable with diagnostic criteria or individual treatment goals.

How fast does Testosterone respond to change?

Levels vary during the day and between measurements. Ask your clinician whether and when repeat testing is appropriate.

Testosterone feeds the hormonal dial, and read it alongside Free Testosterone · TSH · Fasting Insulin · Estradiol.

Ready to act on it? How to raise Testosterone ranks the interventions by leverage and says what does not work.

All biomarkers

Sources and further reading

These sources provide general context; calculator scoring ranges are not clinical treatment targets.

Not medical advice. These are longevity-optimised reference ranges, which are deliberately stricter than standard clinical "normal" values. A value outside them does not mean you have a disease. Speak to a qualified healthcare professional before changing medication, supplements or training. Full disclaimer.
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What is a good Testosterone level?

The longevity-optimised target used in this calculator is 600–900 ng/dL total (men), 15–70 ng/dL (women). Reference intervals depend on the laboratory, assay and population. One harmonised interval of 264–916 ng/dL was derived from healthy nonobese men aged 19–39; it is not a universal diagnostic or treatment range.

Why is this target stricter than the range on my lab report?

Reference intervals describe a selected reference population and depend on the assay. They are not interchangeable with diagnostic criteria or individual treatment goals.

How fast does Testosterone respond to change?

Levels vary during the day and between measurements. Ask your clinician whether and when repeat testing is appropriate.

What is biological age?

Chronological age counts birthdays. Biological age estimates how old your body appears to be functioning, based on measurable biomarkers. Two people born the same year can differ by a decade or more in vascular stiffness, insulin signalling or cardiorespiratory fitness. Biological age makes that gap explicit — and unlike your birthday, it can move in either direction.

How is the Longevity Score calculated?

Each biomarker you enter is scored against longevity-optimised reference ranges and grouped into one of eight dials. Every dial produces its own biological age, and those are combined using fixed weights into a single composite, then expressed as a Longevity Score from 0 to 100. The weighting reflects how strongly each system predicts healthspan: structural and vascular carry the most, hormonal the least.

Do I need all 53 biomarkers?

No. The short form contains a subset of scoring inputs plus context-only fields, and you can leave any of them blank. It is not a recommendation to obtain tests. Missing values are excluded from the calculation — never treated as zero or as 'normal'. A dial with no scored data is dropped entirely and the remaining weights renormalise.

What can I measure without a blood test?

Some inputs can be measured without bloodwork. Blood pressure needs a home cuff and waist-to-height needs a tape measure. Wearable estimates vary; the floor-based sitting-rising test carries a fall risk and should only be attempted if safe.

Is this an anti-aging calculator? Is it a healthspan calculator?

Both terms describe what this tool does, and which one fits depends on what you are asking. "Anti-aging" is the term most people search, and loosely means anything aimed at slowing or reversing age-related decline — this tool fits that description if you score your dials and act on what you find. "Healthspan calculator" is the more precise term: healthspan is the number of years lived without serious chronic disease or disability, and that cannot be measured directly, so this tool scores eight systems that each function as an early-warning proxy for it. Either way, the method is the same: real biomarkers, published thresholds, no vanity-metric framing.

Why don't you have a quick quiz that skips biomarkers entirely?

Several popular tools ask only about habits — exercise days, sleep hours, smoking, diet quality — and return a single precise-looking age. We looked at the research behind that approach and chose not to build it. Published studies do show real, individually-measured links between specific habits and epigenetic age acceleration, but those effect sizes come from different study populations, different DNA-methylation clocks and different measurement units. Adding them together into one number is not something the underlying research actually supports — it produces a precise-looking result built on an imprecise method. Our dials use direct physiological measurements instead: a real blood pressure reading, a real VO₂ max, a real ApoB value. Several dials score from home-measurable data alone with no quiz-guessing involved — see what you can measure without a blood test, above.

Why are your 'optimal' ranges stricter than my lab's normal range?

Standard reference ranges describe what is common in a general population, which now includes a great deal of metabolic dysfunction. They are tuned to flag disease, not to identify what is optimal for a long healthspan. A fasting insulin of 20 µIU/mL sits inside most labs' normal range and is strongly associated with insulin resistance. This tool uses longevity-optimised thresholds instead, so a flag here means room for optimisation — not a diagnosis.

All questions