How Many Calories Does Running Burn? The Real Numbers (and Why Your Watch Is Wrong)
A calories-burned-running calculator you can do in your head, full charts by body weight, pace, and distance, and the research on how far off wrist-based estimates actually are.
Quick answer
Running burns roughly 1 kilocalorie per kilogram of body weight per kilometre, or about 0.72 kcal per pound per mile, and that figure is close to independent of pace for most runners. A 70 kg (154 lb) runner therefore burns about 70 kcal per kilometre and about 110 kcal per mile: roughly 350 kcal for a 5K, 700 kcal for a 10K, and about 2,950 kcal for a marathon. Wrist-worn devices report energy expenditure with median errors above 27 percent even in the best-performing models, so treat any watch number as an estimate with a wide band rather than a measurement.
Almost every runner has stood in a kitchen after a long run doing the same arithmetic: the watch says 940 calories, so what does that buy? The number matters, because eating far under it wrecks recovery and eating far over it quietly undoes a body-composition goal. The problem is that the number on your wrist is one of the least accurate things your watch reports, and the rule of thumb it is competing with is both simpler and, for most runners, closer to the truth.
This guide gives you the arithmetic, the charts, the correction factors that actually change the answer, and the research on how far off consumer devices are. Then it does the part most calculators skip: turning an energy number into what to eat.
The One-Line Calculator: 1 kcal per Kilogram per Kilometre
The energy cost of running has been measured in laboratories for the better part of a century, and it collapses to something you can do in your head. Running costs approximately 1 kilocalorie for every kilogram of body mass you move over every kilometre of ground. In imperial units that is roughly 0.72 kilocalories per pound per mile.
- Metric: body weight in kg × distance in km ≈ calories burned.
- Imperial: body weight in lb × miles × 0.72 ≈ calories burned.
- A 70 kg runner: about 70 kcal per km, about 113 kcal per mile.
- A 154 lb runner: about 111 kcal per mile, about 69 kcal per km.
The surprising part is what is missing from the formula: pace. Within the range most people run, the total energy needed to cover a fixed distance changes only modestly with speed. Running a 10K in 45 minutes and running the same 10K in 60 minutes cost roughly the same total energy, because you are moving the same mass the same distance. Faster running burns more calories per minute, not dramatically more per kilometre. Walking is the genuine exception, because walking is mechanically cheaper per unit distance than running until you approach a very brisk pace.
Calories Burned Running by Body Weight and Distance
These are gross estimates on flat ground at a steady effort, calculated from the 1 kcal/kg/km relationship and rounded. Find the row closest to your body weight.
| Body weight | Per mile | 5K | 10K | Half marathon | Marathon |
|---|---|---|---|---|---|
| 50 kg / 110 lb | 80 kcal | 250 kcal | 500 kcal | 1,055 kcal | 2,110 kcal |
| 60 kg / 132 lb | 97 kcal | 300 kcal | 600 kcal | 1,266 kcal | 2,532 kcal |
| 70 kg / 154 lb | 113 kcal | 350 kcal | 700 kcal | 1,477 kcal | 2,954 kcal |
| 80 kg / 176 lb | 129 kcal | 400 kcal | 800 kcal | 1,688 kcal | 3,376 kcal |
| 90 kg / 198 lb | 145 kcal | 450 kcal | 900 kcal | 1,899 kcal | 3,798 kcal |
| 100 kg / 220 lb | 161 kcal | 500 kcal | 1,000 kcal | 2,110 kcal | 4,220 kcal |
Two things fall out of that table immediately. A marathon costs a normal-sized runner roughly a full day of maintenance energy, which is why the day after a marathon is not the day to diet. And a 5K, for all the effort it takes, costs about the same as one large bagel with peanut butter. Runners routinely overestimate what short hard sessions buy them and underestimate what long easy sessions demand.
Gross vs Net: The 10 to 15 Percent Every Calculator Ignores
Every number above is gross energy expenditure: the total your body used during the run, including the energy it would have spent sitting on the couch for the same period. If your goal is body composition, the honest figure is net: the extra energy the run cost you.
Resting metabolism runs at roughly 1 kcal per kilogram of body weight per hour. So a 70 kg runner sitting still for an hour spends about 70 kcal anyway. A one-hour run showing 700 gross kcal delivered about 630 kcal of extra expenditure. For a single run the difference is small. Across a 60-kilometre week it is a few hundred calories, and that is exactly the size of the error that makes a deficit stall or a gain creep.
| Session | Gross (70 kg runner) | Approx. net | Practical read |
|---|---|---|---|
| 30 min easy, 5 km | 350 kcal | ~315 kcal | A normal snack, not a licence for dessert |
| 60 min steady, 10 km | 700 kcal | ~630 kcal | A real meal is warranted |
| 2 h long run, 20 km | 1,400 kcal | ~1,260 kcal | Needs fuel during, not just after |
| 3.5 h marathon | 2,950 kcal | ~2,700 kcal | Cannot be replaced in one sitting |
What Actually Changes the Number
Pace barely moves the total. These things genuinely do, and they are the corrections worth applying.
| Factor | Effect on energy cost | How to adjust |
|---|---|---|
| Uphill running | Substantially higher; climbing costs extra work against gravity | Add roughly 10 percent per 1 percent of average grade |
| Downhill running | Slightly lower energy, much higher muscle damage | Do not reduce recovery food because the calorie count dipped |
| Soft ground, sand, snow, trail | Higher, sometimes far higher | Treat a trail hour as a road hour plus 10 to 30 percent |
| Treadmill at 0 percent | Slightly lower than outdoors, no air resistance | Set 1 percent grade to approximate outdoor cost |
| Heat and humidity | Higher at the same pace | Expect a higher heart rate at unchanged energy demand |
| Carrying a pack or vest | Higher in direct proportion to added mass | Add pack weight to body weight in the formula |
| Wind | Higher into a headwind, small gain with a tailwind | The penalty exceeds the benefit on an out-and-back |
Why Your Watch Is Wrong (And By How Much)
Wrist-worn devices estimate energy expenditure from heart rate, motion, and your entered profile. Heart rate is a proxy for effort, not for energy, and it drifts with heat, dehydration, caffeine, stress, and sleep. Stanford researchers tested seven consumer wearables against clinical indirect calorimetry and found that none produced acceptable energy-expenditure accuracy: the best device had a median error rate of about 27 percent, and the worst exceeded 90 percent. Heart-rate measurement itself was good. The calorie conversion was not.
A 27 percent error on a 700 kcal run is nearly 200 kcal in either direction, every single run. That is why a runner who eats back exactly what the watch says can gain weight for months while doing everything the screen told them.
- Devices usually report gross, not net, so part of the overestimate is definitional.
- Strength work, hill repeats, and stop-start sessions are estimated worst, because heart rate stays high while mechanical work is low.
- Steady road running is estimated best, because it is closest to the model the device was calibrated on.
- Errors are consistent per person: if your watch reads 20 percent high for you, it usually reads about 20 percent high every time, which makes it useful for comparing your own runs even when the absolute value is wrong.
The practical policy: use the distance-based estimate for planning how much to eat, and use your watch for comparing today against last Tuesday. Do not use the watch number as a budget.
Calories Are the Wrong Question Anyway
Here is the part almost no calories-burned-running calculator will tell you. Energy is not the limiting factor in a hard run. Carbohydrate is. Your body stores tens of thousands of calories as fat and only about 1,500 to 2,000 kcal as muscle and liver glycogen, and it is the glycogen that runs out at mile 20.
So the useful decomposition of a run is not "I burned 1,400 calories". It is "I used roughly 200 to 250 grams of carbohydrate, of which I replaced 60 during the run, so I am 150 grams short and I have a quality session tomorrow morning." That is an actionable sentence. The calorie total is not.
| Run | Approx. energy | Approx. carbohydrate used | What to replace first |
|---|---|---|---|
| 45 min easy | 500 kcal | 40 to 60 g | Normal next meal is enough |
| 75 min moderate | 875 kcal | 90 to 130 g | Carbohydrate plus 20 to 30 g protein within a couple of hours |
| 2 h long run | 1,400 kcal | 150 to 220 g | Fuel during the run; then carbs plus protein |
| 2 h with intervals | 1,500 kcal | 200 to 280 g | Aggressive carbohydrate replacement if training again inside 24 hours |
The proportion of fuel that comes from carbohydrate rises steeply with intensity. An easy jog runs largely on fat. A threshold session runs mostly on carbohydrate. Two runs that show an identical calorie total on your watch can leave you in completely different states.
How Much of It Should You Eat Back?
This is where the number becomes a decision, and the answer depends on what you are training for.
| Goal | How much of the run to replace | Why |
|---|---|---|
| Performance in a build block | Effectively all of it | Under-fuelling in a build block is the fastest route to stalled adaptation and injury |
| Gradual fat loss while training | Most of it; hold a small daily deficit, not a per-run one | Deficits taken out of training days damage the sessions that matter |
| Race week | All of it, plus a deliberate carbohydrate top-up | The goal is full glycogen, not a tidy ledger |
| Easy or rest days | Eat less carbohydrate, hold protein steady | Carbohydrate need moves with training; protein need does not |
The pattern that works is to move carbohydrate around your training rather than shrinking everything uniformly. That is also the pattern almost nobody executes by hand, because it means recalculating every day against a session that keeps changing.
Mavr reads the run you actually did and rebuilds the day around it: carbs, protein, and meals sized to the session rather than to a wrist estimate.
Frequently Asked Questions
How many calories does running a mile burn?
Roughly 0.72 kcal per pound of body weight per mile. A 150 lb runner burns about 108 kcal per mile, a 200 lb runner about 144 kcal. Pace changes this far less than most people expect.
How many calories does a 5K burn?
About 350 kcal for a 70 kg (154 lb) runner, scaling directly with body weight: roughly 250 kcal at 50 kg and 500 kcal at 100 kg. That is gross energy, so the extra cost above resting is about 10 percent lower.
How many calories does a marathon burn?
Roughly 2,600 to 3,400 kcal for most runners, close to body weight in kg multiplied by 42. It is approximately a full day of maintenance energy on top of your normal day, which is why marathon recovery takes days of eating, not one large meal.
Does running faster burn more calories?
Per minute, yes. Per mile, only slightly. Covering the same distance faster burns marginally more total energy but takes less time, so the totals end up close. Faster running does shift the fuel mix strongly toward carbohydrate.
Why does my watch say I burned more calories than the calculator?
Wrist devices infer energy from heart rate, which rises with heat, dehydration, caffeine, and fatigue independently of energy cost. Independent testing has found median energy-expenditure errors above 27 percent even for the best consumer devices. Use the watch to compare your own runs, not to set a food budget.
Should I eat back the calories I burned running?
In a training block, yes, essentially all of them. If you are losing weight, hold a small deficit across the week rather than taking it out of the days you train hardest, and never take it out of race week.
Sources
Sources and official references
- 1.Accuracy in Wrist-Worn, Sensor-Based Measurements of Heart Rate and Energy Expenditure in a Diverse CohortJournal of Personalized Medicine (Shcherbina et al., 2026) · Median energy-expenditure error rates of 27 to 93 percent across seven consumer wearables
- 2.2026 Compendium of Physical Activities: A Second Update of Codes and MET ValuesMedicine and Science in Sports and Exercise (Ainsworth et al., 2026) · Reference MET values used by most calorie calculators
- 3.The Energy Cost of RunningJournal of Applied Physiology (Margaria et al., 1963) · The classic measurement behind the roughly 1 kcal per kg per km relationship
- 4.Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and ACSM: Nutrition and Athletic PerformanceMedicine and Science in Sports and Exercise (Thomas et al., 2026) · Energy availability and daily carbohydrate targets by training load
Prompt ideas for AI assistants
- “How many calories did my long run actually burn?”
- “How much should I eat back after a 10 mile run?”
- “Why is my watch calorie count higher than my running app?”
Mavr converts each run into carbohydrate, protein, and calorie targets for the rest of the day, so the burn number becomes a meal plan rather than trivia.
Written by
Mavr Sports Nutrition Team
The Mavr sports-nutrition team translates peer-reviewed endurance research (Jeukendrup, Burke, the ISSN) into daily fueling for runners and triathletes.