The Calorie Burn Index
How many calories do you actually burn?
Wearables do their best, but if you want to hit your goals, you need to know what your body actually burns.
Enter your weight, your steps, and your treadmill settings. Every number is based on metabolic testing and research (cited at the bottom).
Enter a weight between 60 and 700 lb (27–318 kg).
Your steps
Slide to your daily step count.
Your treadmill workout
Set your speed, incline, and time to see what you'd burn.
Every speed and incline
For your weight. Tap any cell to load it.
All numbers here are active calories: what the activity burns on top of what your body burns at rest. That's the same idea as "active calories" on your watch.
Find your calories for other tests
Everything I've measured beyond the treadmill, scaled to you.
Enter a weight between 60 and 700 lb (27–318 kg).
My tested workouts
Active calories for your workout length, from my own metabolic tests.
Intensity is relative, and it's one of the biggest factors in how many calories you burn. The tags show how hard each test was for me. The same pace can feel easy to a trained runner and very hard to a beginner, but at the same speed and incline, both burn about the same.
Rowers, bikes, and ski ergs
On an erg, calories follow the watts you push. Enter your average watts from the monitor.
Resting metabolic rate
What your body burns just staying alive. Add it to your active calories for your total daily burn.
Want your real numbers instead of estimates?
Benchmark measures resting metabolism, VO2 max, and body composition directly, so your plan is built on your data.
How this is calculated
Where each number comes from and how it's scaled to you.
Active calories
Every number on this page is active calories: the energy an activity costs on top of what you'd burn anyway at rest. It's the same idea as "active calories" on an Apple Watch or Garmin, so you can compare them directly. Your total for the day is your resting metabolic rate plus your active calories, plus roughly 10% of what you eat for digestion (the thermic effect of food).
Steps
Step calories use a formula derived from Weyand and colleagues (2010), who found the energy cost of walking per kilogram is set by stature. Taller people also take longer steps, so a step-based estimate needs only your steps and weight.
calories = 2.74 × steps × kg ÷ 8,368
Treadmill
The treadmill calculator uses the standard ACSM walking and running equations, adjusted to 13 of my own treadmill tests. The incline part of the walking equation matched my data almost exactly, so it's used as published. Flat walking and running cost less in my tests than the equations predict, so those parts use my measured values.
walking: 0.075 × speed + 1.8 × speed × incline
running: 0.143 × speed + 0.9 × speed × incline
Speed is in meters per minute and incline is a decimal. The result is active oxygen use in ml/kg/min; multiply by your weight in kg and 0.3 for calories per hour.
The METs chart
A MET is a multiple of resting energy use: 1 MET is sitting still, 8 METs costs about eight times that. The chart shows METs for every speed and incline combination using the equations above, so you can compare any setting against the published 2024 Adult Compendium of Physical Activities.
My tests run lower than the Compendium: about 30% lower for walking and 20% lower for running. For example, the Compendium lists 3.0–3.4 mph flat treadmill walking at 3.8 METs, where my data puts 3 mph at about 2.7. I use my numbers because they were measured directly with the same analyzer and protocol for every test.
Above 3.5 mph, walking gets less efficient quickly, so the walking estimate rises faster until it meets the running estimate at 4.5 mph, where most people switch to a jog. Speeds from 4.5 to 10 mph use the running equation.
My tested workouts
Every workout on the Other tests tab comes from my own tests on a KORR Cardio Coach metabolic analyzer, an indirect calorimeter that measures oxygen and carbon dioxide to calculate calories burned. I'm 5'11" and 193 lb with a measured resting rate of 90.6 calories per hour. To get your number, I subtract my resting burn and scale what's left to your weight.
active per hour = (my result − 90.6) × your lb ÷ 193
Intensity
How hard you work is one of the biggest drivers of calorie burn, and intensity is relative. Each test is tagged by how hard it was for me.
- LowEasy enough to do all day.
- Steady stateConversational, an hour or more.
- ModerateReal work, about an hour.
- HighHard, 30 minutes or less.
Ergs
I tested the Concept2 SkiErg, RowErg, and BikeErg and the Rogue Echo Bike at 100, 150, and 200 watts, and draw a straight line through those tests for each machine. My RowErg results rise at almost the same rate per watt as Concept2's published formula but come in lower overall, because Concept2 adds a fixed baseline for moving your body on the slide.
Resting metabolic rate
Estimates use the Mifflin-St Jeor equation, generally the most accurate of the common equations for healthy adults. It lands within about 10% for most people, but some miss by more, which is why a measured RMR always wins.
men: 10 × kg + 6.25 × cm − 5 × age + 5
women: 10 × kg + 6.25 × cm − 5 × age − 161
How accurate is this?
Every estimate shows a ±10% range. Technique, terrain, holding the rails, and how hard you actually pushed all move the number. Fitness level barely changes it: at the same speed and grade, a trained and untrained person of the same weight burn about the same. Fitness changes how hard it feels and how long you can hold it, not the cost per minute.
References
- Weyand, P. G., Smith, B. R., Puyau, M. R., and Butte, N. F. (2010). The mass-specific energy cost of human walking is set by stature. Journal of Experimental Biology 213(23): 3972–3979. doi:10.1242/jeb.048199
- American College of Sports Medicine. ACSM's Guidelines for Exercise Testing and Prescription, metabolic equations for walking and running.
- Herrmann, S. D., Willis, E. A., Ainsworth, B. E., et al. (2024). 2024 Adult Compendium of Physical Activities: A third update of the energy costs of human activities. Journal of Sport and Health Science 13(1): 6–12. doi:10.1016/j.jshs.2023.10.010
- Mifflin, M. D., St Jeor, S. T., Hill, L. A., Scott, B. J., Daugherty, S. A., and Koh, Y. O. (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition 51(2): 241–247.
- Concept2. Calorie calculator and performance monitor formulas. concept2.com/training/calorie-calculator