Calories Burned by Heart Rate Calculator

How this heart rate calorie calculator works

This heart rate calorie calculator estimates the calories you burn during a workout from your average heart rate. Enter your sex, age, weight, average heart rate, and minutes. The main result is the session total in kilocalories (kcal), the unit food labels call calories, with the rate per minute and every number the equation used shown under it.

The equations come from a 2005 study by Keytel and colleagues, who measured 115 regularly exercising adults on a treadmill or an exercise bike. There is one equation for men and one for women. If you know your VO2 max, open VO2 max (optional) and enter it, and the page switches to the study’s second pair of equations, which also use fitness.

The Keytel equations without VO2 max

Each equation gives energy in kilojoules per minute (kJ/min). HR is your average heart rate in beats per minute (bpm), W is your weight in kg, and A is your age in years.

Men: kJ/min = −55.0969 + 0.6309 × HR + 0.1988 × W + 0.2017 × A

Women: kJ/min = −20.4022 + 0.4472 × HR − 0.1263 × W + 0.074 × A

In the women’s equation, weight has a minus sign, so a heavier woman gets a slightly lower estimate at the same heart rate. That is how the paper published it, and this page keeps it. At 30 years and 150 bpm, 60 kg gives 9.9 kcal per minute and 90 kg gives 9.0.

The Keytel equations with VO2 max

The second pair adds V, your VO2 max in ml/kg/min. In the study, these equations explained more of the differences between people than the equations without VO2 max (83% against 73%).

Men: kJ/min = −95.7735 + 0.634 × HR + 0.394 × W + 0.404 × V + 0.271 × A

Women: kJ/min = −59.3954 + 0.450 × HR + 0.103 × W + 0.380 × V + 0.274 × A

The paper prints these as one equation with a shared −59.3954 and an extra −36.3781 for men, which add up to the −95.7735 shown here. Its table gives the same equations with one more decimal place; this page uses the printed equations, which differ from the table by less than 0.03 kcal per minute on the examples below.

From kilojoules to calories

The equations give kilojoules, not calories. This page divides by 4.184, the number of kilojoules in one kilocalorie, and then multiplies by your minutes: kcal per minute = kJ per minute ÷ 4.184, and total kcal = kcal per minute × minutes.

Skipping that step is a common mistake. Several published papers that reuse these equations call the result calories without dividing, which makes the estimate about four times too high. For the default example, 56.19 kJ per minute read as calories would give 1,686 for 30 minutes instead of 403.

Pounds are converted at 1 lb = 0.45359237 kg first. Every step keeps full precision, and only the total is rounded, to a whole kcal. The rate under it is shown to one decimal, so the rate times the minutes can differ from the total slightly.

Heart rate calorie examples

A 35-year-old man weighing 80 kg with an average heart rate of 140 bpm for 30 minutes: −55.0969 + 0.6309 × 140 + 0.1988 × 80 + 0.2017 × 35 = 56.19 kJ per minute. Divided by 4.184, that is 13.43 kcal per minute, or about 403 kcal. With a VO2 max of 50, it is 12.95 kcal per minute, about 389 kcal.

A 30-year-old woman weighing 60 kg at 150 bpm for 45 minutes comes to 9.88 kcal per minute, about 444 kcal. With a VO2 max of 42, it is 9.19 kcal per minute, about 414 kcal.

In pounds, a 45-year-old woman weighing 150 lb (68.04 kg) at 130 bpm for 30 minutes comes to about 233 kcal. A 50-year-old man weighing 200 lb (90.72 kg) at 120 bpm for 60 minutes comes to about 699 kcal, with the label described below, because his age is outside the range the study tested.

Limits: what the study tested

This is an estimate from a lab study, not a measurement. The 115 people in the study exercised regularly, were aged about 18 to 45, weighed 47 to 120 kg, and had a VO2 max from 27 to 81 ml/kg/min. They ran or cycled at three steady effort levels, from moderate to hard, for 10 to 15 minutes each. The result includes the energy your body would use at rest over the same minutes, because the paper does not subtract it.

For any one person, the estimate can be off by roughly 3 to 6 kcal per minute in either direction, based on the study’s own check against measured values. In the study, the equations with VO2 max matched the measured values more closely.

Use your average heart rate for the whole workout, from a chest strap or a watch. The study measured steady running and cycling, so stop-and-go sessions such as weights or intervals are a looser fit.

The paper does not report its heart rates in beats per minute. EVR set 170 bpm as the top of the tested range from the effort levels it does report: up to about 90% of the average maximum heart rate, which was about 184 to 189 bpm.

Below 90 bpm, the page shows no number: at low heart rates, heart rate and energy use stop moving together in a straight line. It also shows no number when the equation gives zero or less, and it treats an average heart rate above 220 bpm as a typing error.

The result carries the label “Outside the range the study tested — rough estimate” when your heart rate is above 170 bpm, your age is under 18 or over 45, your weight is under 47 kg or over 120 kg (103.62 to 264.55 lb), or a VO2 max you enter is under 27 or over 81. The number is still shown.

Other ways to estimate workout calories

Without heart rate data, the calories burned calculator uses a published MET value for the activity, with your weight and minutes. To find a heart rate range for a workout before you start, use the target heart rate calculator. Different methods can give different numbers for the same session.

Source

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. J Sports Sci. 2005;23(3):289–297. doi:10.1080/02640410470001730089.

EVR checked every coefficient against a reprint of the paper’s full text, in both the printed equations and the coefficient tables. The factor of 4.184 kJ per kcal is the thermochemical calorie in NIST Special Publication 811.

Sources last checked: 9 October 2026.

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