# VO2 max calculator: estimate it from a run test or your heart rate

VO2 max is the most oxygen your body can use during hard exercise, in millilitres per kilogram per minute. A lab test measures it; field tests estimate it. The Cooper test uses how far you run in 12 minutes, the 1.5-mile test uses your time, and the heart rate ratio method uses 15.3 × maximum ÷ resting heart rate. Estimates are useful for tracking your own change over months.

## How it works

### Cooper 12-minute run

VO2 max ≈ (metres run − 504.9) ÷ 44.73. Run as far as you can in 12 minutes on a flat track after a good warm-up.

### 1.5-mile run

VO2 max ≈ 3.5 + 483 ÷ time in minutes. A steady, all-out effort over 2.4 km.

### Heart rate ratio (Uth)

VO2 max ≈ 15.3 × maximum ÷ resting heart rate. No running needed, but it depends on a good estimate of maximum heart rate.

## Questions

### What is a good VO2 max?

It depends strongly on age and sex. For many adults in their 30s, roughly 35 to 45 ml/kg/min is around average and above 50 is high. Your own trend matters more than a table.

### How do I improve VO2 max?

Mostly by regular aerobic training: plenty of easy zone 2 work plus one or two sessions a week of hard intervals, such as 4 × 4 minutes. Losing excess body fat also raises it per kilogram.

### Are watch VO2 max numbers accurate?

They are estimates from pace and heart rate, often within a few points of lab values for runners. Compare the same watch over time rather than across devices.

### Is a maximal run test safe for me?

If you are new to hard exercise, have a heart condition, or have symptoms such as chest pain or fainting, talk to a clinician first and use the heart rate method instead.

## Sources

- [Cooper KH. A means of assessing maximal oxygen intake. JAMA 1968](https://pubmed.ncbi.nlm.nih.gov/5694044/)
- [Uth N et al. Estimation of VO2max from the ratio between HRmax and HRrest. Eur J Appl Physiol 2004](https://pubmed.ncbi.nlm.nih.gov/14624296/)

Accurate as of November 12, 2026.

---

Canonical: https://revns.com/tools/vo2-max-calculator
Index of everything: https://revns.com/llms.txt
revns gives training guidance, not medical advice.