How your calories are calculated
The calculator works out your speed, matches it to the published MET value for running at that pace (from the Compendium of Physical Activities — the same reference exercise scientists use), and multiplies by your weight and time: kcal = MET × weight (kg) × hours. Heavier runners burn more at the same pace; faster paces have higher METs.
Reading your pace
Pace (min/km) is the runner's currency. Rough adult reference points: 8:00+/km — jogging/beginner zone, exactly where new runners should live; 6:00–8:00/km — steady recreational running; 5:00–6:00/km — trained runner territory; under 5:00/km — competitive club pace. Progress by running more often before running faster: frequency builds the aerobic base that speed later stands on.
The 10% rule and staying injury-free
Most running injuries come from ramping up too fast. Increase weekly distance by no more than ~10%, keep most runs at a conversational pace, and take at least one full rest day. New or returning runners do brilliantly on run-walk intervals (e.g., 2 min run / 1 min walk) — it builds the same fitness with far less joint stress. Fuel the habit with the calorie calculator and track your engine with the heart rate zones.
Sources & references
- Ainsworth BE, et al. 2011 Compendium of Physical Activities: a second update of codes and MET values. Med Sci Sports Exerc. 2011;43(8):1575–1581.
- Buist I, et al. Predictors of running-related injuries in novice runners. Am J Sports Med. 2010;38(2):273–280.