How are calories burned while running calculated?

From oxygen consumption. The ACSM running equation estimates VO₂ in millilitres per kilogram per minute as 0.2 × speed + 0.9 × speed × grade + 3.5, with speed in metres per minute. Multiplying by body mass and by roughly five kilocalories per litre of oxygen gives the energy rate. It is a physiological model rather than a lookup table, which is why gradient and speed both feed in properly.

Does running faster burn more calories?

Per minute, considerably — roughly twice as much at eighteen kilometres an hour as at eight. Per kilometre, barely at all. Because you finish a given distance sooner when running faster, the two effects almost cancel, and the cost per kilometre varies by under seven percent across that entire range. It actually falls slightly as you speed up, since the fixed resting component is spread over less time.

What is the difference between gross and net calories?

Gross is everything your body spent during the run. Net subtracts what it would have spent anyway had you been resting for the same period — about one kilocalorie per kilogram per hour. For a seventy kilogram runner over an hour that resting share is roughly seventy-four kilocalories out of a gross total near seven hundred and seventy, so about ten percent. Most calculators quote gross alone, which overstates what the run added.

How accurate is this estimate?

It is a reasonable estimate of scale, not a measurement. The ACSM equation is a population average fitted to laboratory data, and real individual cost varies by roughly ten to twenty percent depending on running economy, training state, terrain, footwear and temperature. Wearables are not better — most rely on similar models with less information about you. Use the figure for comparison between runs rather than as an absolute quantity.

How much does running uphill add?

A great deal. The grade term in the equation is 0.9 × speed × gradient, so at ten kilometres an hour a two percent incline adds about eight percent to the cost, five percent adds around twenty, and ten percent adds over forty. This is why hill sessions feel disproportionately hard for the pace on the watch, and why pacing by effort rather than by pace makes sense on a hilly route.

Does body weight change the result?

Directly and proportionally — the equation gives energy per kilogram, so doubling body mass doubles the estimate at the same pace and distance. This is the single most influential input, which is also why comparing raw calorie figures between two runners tells you very little about their relative effort. Cost per kilogram per kilometre is much closer between people than the totals suggest.

Why does the equation not work for walking?

Because walking and running are mechanically different, and ACSM publishes a separate equation for each. The running form applies above about 134 metres per minute — roughly eight kilometres an hour, or a 7:28 kilometre. Below that, walking is more economical than the running equation predicts, so applying it anyway overstates the cost. This page flags it when your pace falls below that threshold.

A MET is a multiple of resting metabolic rate, defined as 3.5 millilitres of oxygen per kilogram per minute. Running at ten kilometres an hour is roughly ten and a half METs, meaning about ten and a half times your resting rate. The unit is useful because it is independent of body weight, so it describes the intensity of an activity rather than the energy any particular person spends doing it.

Do I burn calories after the run as well?

Some, though less than is often claimed. Elevated oxygen consumption after exercise is real but modest for steady running — typically a small percentage of the session's own cost, and larger after harder or longer efforts. It is not accounted for in these figures, and it is not large enough to change the picture materially. The dominant term remains the running itself.

Calories Burned Running Calculator

Estimate the energy cost of a run from your body weight, the distance, the pace and the gradient. This uses the ACSM running equation rather than a lookup table, which means incline and speed both feed in properly instead of being approximated away. Two things here are handled more carefully than mo...

YOUR RUN

BODY WEIGHT

DISTANCE

PACE — mm:ss per km

INCLINE0%

COMMON DISTANCES

THE RUN ITSELF COST

700 kcal

GROSS TOTAL

774 kcal

PER KM

77.4

METs

10.5

Over 1:00:00 the gross figure is 774 kcal, of which about 74 is what your body would have spent resting anyway. The run's own additional cost is the 700 above.

Duration

1:00:00

Speed

10.00 km/h

Per minute

12.9 kcal

Per hour

774 kcal

Per km (gross)

77.4 kcal

Per mile (gross)

124.5 kcal

WHERE THE ENERGY GOES

Not all of it is extra. Your body spends energy continuously, so the grey band is what the same 1:00:00 would have cost sitting still — about 10% of the total here. Most calculators quote only the sum, which overstates what the run actually added.

Speed changes the rate, not really the total. Running faster burns considerably more per minute — but you finish sooner, and the two effects very nearly cancel. Across a doubling of speed the cost per kilometre moves by only a few percent, and slightly downwards, because the fixed resting component is spread over less time. Distance is what determines the total; pace mostly determines how long it takes.

How much to trust the number. This uses the ACSM running equation, which is a population average fitted to laboratory data. Individual metabolic cost varies by roughly ten to twenty percent for reasons including running economy, fitness, terrain and temperature, and wearable devices carry at least as much error. It is a reasonable estimate of scale, not a measurement.

Created with❤️byeaglecalculator.com

HOW TO USE

1
Enter your body weight in kilograms or pounds. Energy cost scales directly with mass, so this is the input that matters most.
2
Enter the distance and your pace. Pace is mm:ss per kilometre or per mile, matching whichever distance unit you picked.
3
Add a gradient if the run was hilly. The ACSM equation includes a grade term, so a five percent incline adds around twenty percent to the cost at the same speed.
4
Read both numbers. The headline is the run's own additional cost; the gross total beside it includes what your body would have spent resting over the same period.

THE FORMULAS

ACSM runningVO₂ = 0.2·S + 0.9·S·G + 3.5

S and Gmetres/min, grade as a fraction

Energykcal/min = VO₂ · kg ÷ 1000 · 5

One MET3.5 ml/kg/min

Resting≈ 1 kcal per kg per hour

Net costgross − resting over the same time

Valid above134 m/min, about 8 km/h

Per kilometrenearly independent of pace

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Last updated: July 28, 2026 · ACSM running equation · An estimate for general interest, not nutritional or medical advice · Eagle-eyed accuracy for every calculation.