How many calories does a half marathon burn? Enter your weight and pace — get your result instantly.
| Weight | kcal burned | Finish time |
|---|---|---|
| 50 kg / 110 lbs | ~1,030 kcal | ~2:21 |
| 60 kg / 132 lbs | ~1,235 kcal | ~2:21 |
| 70 kg / 154 lbs | ~1,441 kcal | ~2:21 |
| 80 kg / 176 lbs | ~1,647 kcal | ~2:21 |
| 90 kg / 198 lbs | ~1,853 kcal | ~2:21 |
| 100 kg / 220 lbs | ~2,058 kcal | ~2:21 |
A half marathon (21.1 km / 13.1 miles) burns approximately 1,200–2,100 kcal depending on body weight. The reliable rule: 1 kcal per kg per km. A 70 kg runner burns roughly 70 × 21.1 = 1,477 kcal — nearly a full day's worth of calories for a moderately active person.
A half marathon burns roughly 2.1× more calories than a 10K at the same pace and weight. If you burn 700 kcal for a 10K, expect ~1,450 kcal for a half marathon. The extra distance also elevates post-race calorie burn (EPOC) for 12–24 hours afterward.
For most runners, yes — especially those finishing in over 90 minutes. Your body stores roughly 1,500–2,000 kcal of glycogen. A half marathon can deplete this entirely. Taking 1–2 energy gels or chews (100–200 kcal each) from around 45 minutes in helps maintain pace and prevents hitting the wall.
While distance is the main driver, pace affects the MET value. A 70 kg runner finishes a half marathon in ~2:20 at easy pace (9 km/h) burning ~1,440 kcal, vs ~1:35 at fast pace (13 km/h) burning ~1,350 kcal — slightly less because higher pace has shorter duration. Either way, it's a massive calorie burn.
Here are estimated calories burned running a half marathon (21.1 km) at moderate pace by body weight:
50 kg — approximately 1,050 kcal · 60 kg — approximately 1,260 kcal · 70 kg — approximately 1,470 kcal · 80 kg — approximately 1,680 kcal · 90 kg — approximately 1,890 kcal · 100 kg — approximately 2,100 kcal
At a fast race pace, total calories burned are slightly lower (approximately 5–10% less) because the shorter duration partially offsets the higher intensity. At a slow pace, the numbers are similar or slightly higher due to the extended time on feet.
A typical 12-week half marathon training plan involves 4–5 running sessions per week, with weekly mileage building from around 25 km to 50 km at peak. For a 70 kg runner, this translates to approximately 1,750–3,500 kcal burned through running per week. Over the full 12-week cycle, a dedicated runner can expect to burn 21,000–42,000 kcal through training — the equivalent of 3–5 kg of fat if diet remains stable.
In practice, increased training volume also increases appetite, so actual fat loss during a training block is often more modest — typically 1–3 kg over 12 weeks. Body composition tends to improve more than the scale suggests, as muscle is built simultaneously with fat being burned.
The average human body stores approximately 1,500–2,000 kcal of glycogen — enough to fuel roughly 90 minutes of running at moderate intensity. Since most runners take more than 90 minutes to finish a half marathon, some mid-race fuelling is important to maintain energy and pace.
A practical fuelling strategy: take an energy gel or 2–3 chews every 30–45 minutes from around 45 minutes into the race. Each gel provides approximately 100 kcal. For a 2-hour half marathon, this means 2–3 gels, replacing approximately 200–300 kcal of the total 1,200–2,100 kcal burned. The goal is not to replace every calorie burned, but to keep blood sugar stable and glycogen stores from fully depleting.