Running / 005
Calories burned running
Energy cost from your weight, the distance and the time, using the published ACSM metabolic equation — with the equation, its limits and the rounding on the page.
Read the guide: kcal per km and per mile for eight body weights at four speeds
Energy cost, gross
ACSMNext / The same run
Other ways to read
the same effort.
The equation, written out
This page uses the ACSM metabolic equation for running, published in ACSM's Guidelines for Exercise Testing and Prescription. It estimates the oxygen cost of running at a given speed and grade, then converts that oxygen into energy:
VO2 (ml/kg/min) = 0.2 × speed + 0.9 × speed × grade + 3.5, where speed is in meters per minute and grade is the incline as a decimal fraction. The 0.2 term is the horizontal cost of moving, the 0.9 term is the extra cost of climbing, and the 3.5 is resting metabolism.
Oxygen then becomes energy at roughly five kilocalories per liter consumed: kcal/min = VO2 × body mass in kg ÷ 1000 × 5, and the total is that rate multiplied by the minutes you ran.
Worked through: 80 kg over 10 km in an hour is 166.67 m/min. On the flat that is 0.2 × 166.67 + 3.5 = 36.83 ml/kg/min, which is 36.83 × 80 ÷ 1000 × 5 = 14.73 kcal/min, and over sixty minutes, 884 kcal. Nothing is rounded along the way: the total reaches the screen rounded to a whole kilocalorie, and the per-minute and per-unit rates to one decimal.
Where the equation stops working
ACSM gives the running equation a floor: it is intended for speeds above about 134 meters per minute, which is roughly 8 km/h or a 7:30 per kilometer pace. Below that most people are walking, or jogging in a way that behaves more like walking, and the walking equation has different coefficients. This page still returns a figure under that speed, because refusing to answer is less useful than answering with a warning, but it flags the result when you are below the threshold.
Two more limits worth knowing. The figure is gross, so it includes the energy you would have spent existing during that hour rather than only the cost of the run. And the grade term assumes a known, steady incline, which is a treadmill. Outdoor hills change gradient constantly and running back down does not refund what going up cost, so a single percentage cannot describe an undulating route.
This is an estimate from a published equation, not a measurement and not advice about diet, weight or health. It cannot account for your running economy, your fitness, the terrain, the weather, or what you were carrying. Do not use it to justify a calorie deficit or a target intake: speak to a doctor or a registered dietitian about those, particularly if you are managing a health condition or changing how much you eat.
Common questions
How many calories does running a 10K burn?
For an 80 kg runner covering 10 km in an hour on the flat, this equation gives about 884 kilocalories. Change the weight and the figure moves almost in proportion, because body mass is a straight multiplier in the arithmetic. Change the time and it moves far less than people expect: covering the same ten kilometers faster burns slightly more per minute but over fewer minutes.
Does running faster burn more calories?
Per minute, clearly yes. Over a fixed distance, barely. The oxygen cost of running rises close to linearly with speed, so halving your time roughly doubles the rate and roughly halves the duration, and the two largely cancel. What actually moves the total over a set distance is your body mass and the hill you ran up.
Is this gross or net calories?
Gross. The figure includes the energy you would have spent anyway just being alive for that hour, which is roughly one kilocalorie per kilogram per hour. Subtract that if you want the net cost of the run itself — for an 80 kg runner over an hour it is in the region of 80 kilocalories, so the net figure is meaningfully smaller than the gross one.
Why does my watch give a different number?
Watches usually fold in heart rate, age, sex and a proprietary model, and most report net rather than gross. This page uses one published equation with no hidden terms, which makes it reproducible but not personalized. Neither figure is measured: outside a lab with a gas analyser, every calorie number you see is a model.
Does the incline setting matter much?
A great deal. The grade term is multiplied by speed, so at a given pace each percent of incline adds meaningfully to the oxygen cost — a steady 1 percent is a small change, while 8 or 10 percent is a different workout entirely. The equation covers treadmill grades, where the incline is known. Outdoor hills rarely hold one gradient long enough for a single figure to describe them.