Walking calorie calculator

The double-counting nobody mentions

A MET is defined as one kilocalorie per kilogram of body weight per hour, roughly the energy cost of sitting quietly. When the Compendium lists brisk walking at 4.8 METs, it means 4.8 times your resting rate — and one of those 4.8 is the resting rate itself.

That matters because your resting metabolism is already inside your maintenance calories. If you count the full 4.8 as new energy spent and then subtract it from a maintenance figure that already contains the 1, you have counted the same calories twice. Only the 3.8 METs above resting are genuinely new.

At walking intensities that is a 20 to 30% difference, and it runs in the direction that makes the calculator look more encouraging. The panel above prints both, and uses the net figure for the projection.

The standard MET is not your MET

A MET is anchored to a fixed referent: 3.5 mL of oxygen per kilogram per minute, assumed to be everybody’s resting metabolic rate. It is not. Real resting metabolism varies with age, sex, body mass and height, and the Compendium’s own authors report that the standard MET misclassifies the intensity category 12.2% of the time compared with measured MET values — with greater misclassification in people who are overweight, older, less fit, or women.

That is a systematic bias, not noise, and it runs against the people most likely to be using a walking calculator. The Compendium publishes a correction for it that divides the 3.5 referent by your own predicted resting rate — and, notably, it specifies the Harris-Benedict equation for that prediction, while the Hall weight model this site uses specifies Mifflin-St Jeor. The two disagree by well over a hundred calories a day for many adults. Both are in the form above, deliberately, so you can see how much of the answer is estimate.

The MET values here are from the 2024 Adult Compendium, the third update of the series. We use the current edition; we could not verify the superseded 2011 values from a primary document, so this page does not print a before-and-after comparison it cannot stand behind.

Walking beats an equal-calorie diet cut, until it does not

This one surprises people, and it falls straight out of the model. Cutting 300 calories of food and burning 300 calories on a walk are not the same intervention. Eating less triggers two reductions in expenditure that walking does not touch: the thermic effect of feeding drops by about a tenth of the calories you removed, and adaptive thermogenesis takes about another seventh over the following fortnight. Together that is roughly a quarter of the diet cut, given back.

Walking pays no such tax. What it pays instead is a shrinking bill: its cost is proportional to the weight you are carrying, so the same walk buys less every month.

The result is a crossover, which the Hall appendix derives explicitly. Below a certain intervention size, physical activity produces more weight loss than diet restriction; above it, diet restriction wins. Our implementation puts a 45-minute brisk walk comfortably on the activity side of that line and a 1,200 calorie daily change on the diet side of it — and both results are asserted in the test file that ships with this site.

What these numbers cannot know

• Hills. Every MET value here is for level ground on a firm surface. The Compendium lists grade walking separately and this calculator does not include it.
• You, specifically. The standard MET fixes resting metabolism at 3.5 mL of oxygen per kg per minute for everybody. The Compendium’s own authors note that this misclassifies exercise intensity about 12% of the time, and does so more often in people who are overweight, older, less fit, or female.
• What you do with the rest of the day. Adding a walk and then sitting more, or eating more, is a real and well-documented pattern. The model assumes the rest of your life is unchanged, because it has no way to see otherwise.

Next

• How many steps to lose weight — the same maths from a step count and a cadence.
• Weight loss timeline calculator — the food lever, on real dates.
• Macro calculator — what to eat around it.