Free tool
Rucking calorie calculator
Pandolf equation plus the modern under-prediction correction. Shows the MET-only estimate alongside so you can see what your watch is leaving on the table.
Total burn
391
kcal over 60 min (6.5 kcal/min)
- Raw Pandolf
- 331 kcal
- With correction
- 391 kcal
- Unloaded baseline
- 295 kcal
- Load uplift
- +12%
- MET-only estimate
- 350 kcal
- vs your watch (likely)
- +12%
The MET-only estimate is what most fitness watches and apps use when they don't know you're carrying a load. The Pandolf number is what the US Army uses to plan ruck marches.
Buy it back
Open the CalBurndown app to log 391 kcal and see what to walk, ruck, or stand to stay on budget.
Formula & assumptions
The Pandolf equation predicts metabolic rate (in watts) for a person walking with an external load:
M (W) = 1.5·W
+ 2.0·(W + L)·(L / W)²
+ η·(W + L)·(1.5·V² + 0.35·V·G)Where W = body weight (kg), L = load (kg), V = walking speed (m/s), G = grade (%), and η = terrain factor (1.0 pavement → 1.8 swamp/snow).
We convert watts to kcal/min via kcal/min = W × 60 / 4184, then multiply by duration. The optional ×1.18 factor compensates for the consistent under-prediction modern validation studies have found in the raw 1977 formula.
The MET comparison uses speed-interpolated walking METs from the Compendium of Physical Activities, applied to your combined body + load mass. This is what most consumer wearables use when they don't know you're rucking, and it generally under-counts load uplift.
References
Pandolf, K. B., Givoni, B., & Goldman, R. F. (1977). Predicting energy expenditure with loads while standing or walking very slowly. Journal of Applied Physiology, 43(4), 577–581.
Ainsworth, B. E. et al. (2011). Compendium of Physical Activities: a second update of codes and MET values. Medicine & Science in Sports & Exercise, 43(8), 1575–1581.