Rucking Calorie Calculator
Estimate the energy cost of walking under load with the military-grade Pandolf equation.
More than a step count
Rucking burns far more than unloaded walking because you carry weight over ground.
It is an estimate
Real burn varies with fitness, gait, and conditions — treat the number as a guide.
What is rucking, and why does it burn so much?
Walking with a loaded pack
Rucking is walking while carrying a weighted pack — a staple of military training that has become popular for everyday fitness. Because you move both your body and the load against gravity and friction, rucking burns substantially more energy than walking the same distance empty-handed. According to physical-activity research, carrying even a moderate load raises the metabolic cost steeply, which is why a brisk ruck can rival jogging for calorie burn at a far lower impact.
This calculator uses the Pandolf equation, the standard model for the energy cost of load carriage, developed for the US Army.
M = 1.5·W + 2.0·(W+L)·(L/W)² + η·(W+L)·(1.5·V² + 0.35·V·G)Here W is your body mass in kilograms, L is the load, V is speed in metres per second, G is the grade in percent, and η (eta) is a terrain factor. Metabolic rate M comes out in watts, which we convert to calories using time and the fact that one kilocalorie is 4,184 joules. Notice that speed is squared, so going faster costs disproportionately more, and that the load term scales with how heavy the pack is relative to you. Studies show this model predicts load-carriage energy cost well for level and uphill walking across a range of loads and paces.
A 75 kg person rucks for an hour at 5 km/h on flat pavement with a 20 kg pack.
Baseline cost
1.5 × 75 = 112.5 watts just to move your body.Load penalty
2.0 × 95 × (20/75)² ≈ 13.5 watts for carrying the pack.Movement cost
On a paved road (η = 1.0) at 1.39 m/s on the level: 1.0 × 95 × (1.5 × 1.39²) ≈ 275 watts.Convert to calories
Total ≈ 401 watts → 401 × 3600 ÷ 4184 ≈ 345 kcal for the hour.
Three inputs dominate the result, so they are the ones worth getting right.
Load and body weight
A heavier pack — and a heavier you — both raise the cost, since the whole loaded mass is moved every step.
Speed
The speed term is squared, so picking up the pace from 4 to 6 km/h adds far more than a proportional amount of burn.
Terrain and grade
Soft sand can more than double the cost of the same load, and every percent of uphill grade adds to the total.
If you want to compare rucking with other activities, our calories burned calculator covers dozens of exercises by MET value, and our BMI calculator puts your body weight in context. Together they help you see where a ruck fits in a weekly plan.
The headline figure is the total calories for the session; the hourly rate and metabolic power show the intensity behind it. As a rough sense check, a loaded ruck typically burns two to three times what unloaded walking would over the same time, and heavy packs on rough ground push that higher. Use the number to plan fuelling and recovery, not as a precise measurement: individual metabolism, walking economy, heat, and how the load is packed all shift the real cost. According to general fitness guidance, the safest way to raise your burn is to add load and grade gradually rather than all at once, letting your joints and connective tissue adapt to carrying weight.
The model is solid; your body is individual.
An estimate, not medical advice
The Pandolf equation estimates energy cost for level and uphill walking and was validated on healthy adults; it does not model downhill descents, very light loads at slow speeds, or individual differences in fitness, gait, and heat tolerance, so your real burn will vary. Among its limitations, it can over- or under-estimate at the extremes of speed and load. This calculator is for general fitness and educational purposes and is not medical advice. Rucking with heavy loads stresses the spine, hips, knees, and feet — consult a doctor or healthcare provider before starting a loaded program, especially if you have joint, back, or heart concerns, and build up weight and distance gradually.