What This Calculator Estimates
This calculator estimates how long a workout may need to last to reach a target calorie burn. It uses your body weight and a selected activity level to turn a calorie goal into a rough time estimate.
Formula / Method Used
The calculator estimates calories burned per minute with the common MET-based formula: MET x 3.5 x body weight in kg / 200. It then divides your calorie target by that per-minute estimate to calculate workout duration in minutes.
Worked Example
If your goal is to burn 400 calories, you weigh 70 kg, and you select running with a MET value of 8, the calculator estimates calories burned per minute and then calculates the number of minutes needed to reach the 400-calorie goal.
What the Result Means
The result is a planning estimate, not a guarantee. It can help you compare activities or set a workout target, but real calorie burn varies with pace, fitness level, movement efficiency, and how closely your session matches the chosen intensity.
Common Mistakes
- Choosing an activity intensity that does not match your real workout pace.
- Assuming machine calorie numbers and formula estimates will match exactly.
- Using a stale body-weight estimate after significant change.
- Treating calorie burn as the only meaningful workout goal.
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Frequently Asked Questions
What does the Exercise Duration Calculator estimate?
It estimates how many minutes of a selected activity may be needed to burn a target number of calories.
How does the calculator estimate calories burned per minute?
It uses the selected MET value, your body weight, and a standard calories-burned formula to estimate energy use per minute.
Why do different activities produce different times?
Higher-intensity activities have higher MET values, which means they burn more calories per minute and may require less time.
Is this a medical or training prescription?
No. It is a planning estimate and should not replace personalized medical or training guidance.
When should I recalculate exercise duration?
Recalculate when your target calories, body weight, or activity choice changes.
General Disclaimer
This calculator is for general fitness planning only. It is not medical advice, and actual calorie burn can differ from estimates because of intensity, conditioning, biomechanics, and device measurement differences.
Last updated: May 23, 2026