How to calculate your daily calories (TDEE)

Steps

1. Work out your BMR, or enter your sex, age, weight and height in the daily calories calculator. Here the BMR is 1,648.75.
2. Choose the activity factor: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 active, 1.9 very active.
3. Multiply: 1,648.75 × 1.55 = 2,555.6 calories to maintain your weight.
4. For about 0.5 kg a week of loss, subtract 500: 2,056 calories.
5. For about 0.5 kg a week of gain, add 500: 3,056 calories.

How the activity level changes the answer

For the same man, the calories to maintain his weight are 1,979 if sedentary, 2,267 with light activity, 2,556 with moderate activity, 2,844 if active and 3,133 if very active. The difference between the lowest and highest level is over 1,100 calories a day.

Be honest about your activity. Most people overestimate it, and a desk job with three workouts a week is usually light or moderate, not active.

Where the 500 calories comes from

About 7,700 calories is roughly one kilogram of body fat, so eating 500 fewer calories a day is 3,500 a week, or about 0.5 kg. In practice weight does not change in a perfectly straight line, because water, food in the gut and muscle also change. Use the number as a guide and check your weight over several weeks.

A few cautions

Do not go far below your BMR without medical advice. Children, teenagers, pregnant women and people with medical conditions have different needs. The calculation is an estimate from averages, so adjust it by what happens to your weight. This page gives general information, not medical advice.