What this calculates
Calorie burn estimates for running are based on MET values — Metabolic Equivalent of Task, a measure of how much oxygen a given activity uses relative to sitting at rest. Running has a MET value that increases with pace: a slow jog has a MET of around 7, while fast running above 10 km/h has a MET of 11–14.
The formula is: kilocalories = MET × body weight in kg × duration in hours. For example, a 70 kg runner at a pace that corresponds to MET 10 burning 600 kcal/hour will burn 300 kcal in 30 minutes. This formula comes from the ACSM Compendium of Physical Activities (Ainsworth et al., 2011), the standard reference for MET values in research.
Important caveat: all calorie estimates are approximate. Individual variation in running economy means two runners of identical weight at identical pace can differ by 15–20% in calorie burn. Running surface, weather, gradient, and running form all affect energy cost. Wearable devices use similar MET-based methods plus heart rate models, and their estimates typically differ from actual metabolic measurement (indirect calorimetry) by ±10–20%.
The ACSM Compendium defines MET values by speed bands. This calculator uses the compendium values for running at different pace ranges and interpolates between them. For an explanation of why different calculators give different answers and what the research actually says, see the guide on MET-based calorie estimation.
This calculator also shows the approximate fuel source split (carbohydrate vs fat) at different running intensities, based on the crossover concept and typical zone training research.
How to use this calculator
Enter your body weight, the distance or duration of your run, and your pace. The calculator shows estimated calories burned and the approximate carbohydrate/fat split.
For total daily energy balance, add this to your resting metabolic rate (approximately 1,400–2,000 kcal/day for most adults depending on body size and composition). The running calorie figure is net — above your resting metabolism.
Methodology
MET values from Ainsworth et al. (2011), "2011 Compendium of Physical Activities: A Second Update of Codes and MET Values," Medicine & Science in Sports & Exercise. Calorie formula: kcal = MET × weight_kg × hours. MET values by pace: walking <6 km/h: 3.5; light jog 6–8 km/h: 7.0; moderate run 8–10 km/h: 10.0; vigorous run 10–12 km/h: 11.5; fast run 12–14 km/h: 13.0; racing pace >14 km/h: 14.5.
Full methodology and formula sources →
Frequently asked questions
Why does my watch show a different calorie number?
Different devices use different MET tables and some add heart rate-based corrections. A Garmin watch, a Polar, and this calculator will all produce slightly different estimates. They are all approximations. The ACSM compendium MET values represent population averages; your individual metabolic rate may differ by ±15%.
Does running faster burn more calories per kilometre?
The calorie cost per kilometre is relatively constant across paces for a given runner — roughly 60–80 kcal per km per 70 kg body weight. Faster pace means higher MET and more calories per hour, but the distance is covered faster too. The calorie-per-km figure barely changes. What matters for total burn is total distance, not pace.
Does running on a treadmill burn the same calories?
Slightly fewer, because treadmill running eliminates wind resistance. The difference is small at jogging speeds (1–3%) but increases at faster paces. Treadmill grade adjustments add significant calorie cost: running at 1% grade approximately matches outdoor energy cost at equivalent pace.
Are post-run calories (afterburn / EPOC) included?
No. This calculator estimates energy burned during the run only. Post-exercise oxygen consumption (EPOC) adds a small additional calorie burn — roughly 6–15% of the run's energy expenditure for moderate-intensity running, diminishing quickly over 30–60 minutes after the run ends.