Rucking Calorie Calculator

Pandolf, Givoni, and Goldman published the load-carriage equation in 1977. This calculator implements it to estimate metabolic power in watts from body mass, pack mass, walking speed, grade, and terrain. It then converts watts to estimated calories. The equation is a model, not a measurement of your individual energy use.

Rucking sits between walking and jogging. A typical training pace is about 14:00 to 18:00 per mile (3.3 to 4.3 mph). The calculator accepts approximately 12:14 to 60:00 per mile, matching the walking-speed range used for this implementation of the Pandolf equation.

The Pandolf equation multiplies its speed-and-grade term by a terrain coefficient. This calculator uses 1.0 for pavement, 1.1 for trail, 1.2 for light brush, 2.1 for sand, and 2.5 for snow. Surface depth, compaction, footwear, and whether you follow an existing track still affect your actual cost.

The calculator flags loads above 20 percent of body weight as an internal caution, not an official Army standard or a validated injury threshold. Appropriate load depends on training history, distance, speed, terrain, footwear, health, and the task. Start lighter than a load you already tolerate, progress gradually, and stop for pain, numbness, weakness, or altered gait. Military event requirements are performance standards, not general training prescriptions.

The Pandolf equation adds the pack load to the mass moved and increases the speed-and-grade term for harder terrain. A heavier pack, faster pace, steeper grade, or softer surface therefore raises the estimate. Extreme outputs remain sensitive to the model assumptions, so do not treat the calorie total as a measured value.