The Bruce protocol is the classic treadmill stress test: speed and incline rise every 3 minutes until you can’t continue. How long you last predicts your aerobic capacity.
How to use the Bruce Protocol METs Calculator
- Sex
- Age (years)
- Test time – minutes
- seconds
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Choose your sex, enter your age and the total test time.
Inputs explained
| Field | What to enter |
|---|---|
| Sex | Choose one: Male, Female |
| Age (years) | A number |
| Test time – minutes | A number |
| seconds | A number |
What each result means
- METs achieved = [Estimated VO₂ max]÷3.5
- Stage reached = min(7, floor([T]÷3) + 1)
- Age-predicted maximum heart rate = 192 – 0.007×[Age (years)]^2
Example values
How the main result changes when Age changes and everything else stays at the example values above:
| Age (years) | METs achieved (METs) |
|---|---|
| 20 | 10.3 |
| 30 | 10.3 |
| 40 | 10.3 |
| 50 | 10.3 |
| 60 | 10.3 |
| 80 | 10.3 |
Formula
Men: VO₂ = 14.8 − 1.379T + 0.451T² − 0.012T³ · Women: VO₂ = 4.38T − 3.9 · METs = VO₂ ÷ 3.5 · HRmax = 192 − 0.007 × age² (T in minutes)
Worked example
Inputs — Sex: Male; Age (years): 40; Test time – minutes: 10; seconds: 30.
Results — Estimated VO₂ max = 36.2 ml/kg/min; METs achieved = 10.3 METs; Stage reached = 4; Age-predicted maximum heart rate = 181 bpm; Fitness (METs) = Good.
Key terms
- MET
- Metabolic equivalent – 3.5 ml O₂/kg/min.
Frequently asked questions
What are the Bruce stages?
Stage 1 is 2.7 km/h at 10%; speed and incline rise every 3 minutes.
Is a Bruce test safe?
It is done under medical supervision with ECG monitoring.
What is a good result?
10+ METs is a good fitness level for most adults.
Why are the formulas different for men and women?
They were fitted separately from test data.