Heart Rate Calories Calculator (Keytel)

Calories burned from heart rate

Short answer

Keytel and colleagues predicted exercise energy from heart rate, weight, age and sex in 115 adults. A 35-year-old man weighing 75 kg who averages 140 bpm for 45 minutes burns about 594 kcal. Adding VO2 max makes the estimate more accurate.

Last reviewed 28 October 20261 published sourcesNot medical advice

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Heart rate calories calculator

Use the average heart rate from a steady workout. VO2 max is optional and makes the estimate more accurate.

Enter your age, weight, average heart rate and workout time.

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Calories per 30 minutes by average heart rate (age 35, no VO2 max)
Average heart rate	Man, 75 kg	Woman, 60 kg
100 bpm	215 kcal	139 kcal
120 bpm	305 kcal	203 kcal
140 bpm	396 kcal	267 kcal
160 bpm	486 kcal	331 kcal

Average heart rate

Man, 75 kg

Woman, 60 kg

100 bpm

215 kcal

139 kcal

120 bpm

305 kcal

203 kcal

140 bpm

396 kcal

267 kcal

160 bpm

486 kcal

331 kcal

The Keytel equations

Keytel et al. measured 115 regularly exercising adults aged 18–45 (47–120 kg) during steady exercise at 35%, 62% and 80% of VO2 max, and fitted equations for energy expenditure in kJ per minute (Keytel et al., 2005).

Without VO2 max: men −55.0969 + 0.6309 × HR + 0.1988 × weight + 0.2017 × age; women −20.4022 + 0.4472 × HR − 0.1263 × weight + 0.074 × age. This version explained 73% of the variation (Keytel et al., 2005).

With VO2 max: men −95.7735 + 0.634 × HR + 0.404 × VO2 max + 0.394 × weight + 0.271 × age; women −59.3954 + 0.45 × HR + 0.380 × VO2 max + 0.103 × weight + 0.274 × age. This version explained 83% (Keytel et al., 2005).

Other ways to estimate calories

Without a heart rate, the calories burned calculator uses MET values for each activity. For cycling with a power meter, the cycling calories calculator is more direct.

Common questions

How do you calculate calories from heart rate?

Keytel et al. (2005) give energy in kJ per minute. For men: −55.0969 + 0.6309 × heart rate + 0.1988 × weight (kg) + 0.2017 × age. For women: −20.4022 + 0.4472 × heart rate − 0.1263 × weight + 0.074 × age. Divide by 4.184 for kcal per minute and multiply by the minutes exercised.

Why does adding VO2 max change the answer?

Fitter people burn a different amount at the same heart rate. In the study, the equation with VO2 max explained 83% of the variation in measured energy expenditure, against 73% without it.

Does it work for weight training or intervals?

Less well. The equations come from steady treadmill or cycling exercise at 57–90% of maximum heart rate, so they suit steady cardio best.

Sources

Figures on this page were checked against these publications on 28 October 2026.

Keytel LR, Goedecke JH, Noakes TD, Hiiloskorpi H, Laukkanen R, van der Merwe L, Lambert EV. Prediction of energy expenditure from heart rate monitoring during submaximal exercise. Journal of Sports Sciences. 2005;23(3):289–297. doi.org/10.1080/02640410470001730089

Calories burned from heart rate