Macro and calorie calculator

This calculator is a Mifflin-St Jeor estimate plus two choices this page makes for you: an activity multiplier and a goal offset. It is not a metabolic ward. The inputs are body weight in pounds, height in inches, age, sex, an activity word, and a goal of build, cut, or maintain.

The equation the form runs

Weight is converted to kilograms by multiplying pounds by 0.453592. Height is converted to centimeters by multiplying inches by 2.54. For the male selection the resting estimate is 10 times kilograms, plus 6.25 times centimeters, minus 5 times age, plus 5. For the female selection the constant at the end is minus 161 instead of plus 5. That resting number is then multiplied by the activity factor you picked: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 active, or 1.9 very active. Build adds 300 calories to that product. Cut subtracts 400. Maintain adds nothing. Those three offsets are site choices so the form can return one number. They are not a medical prescription, and a 400-calorie deficit is not automatically the right cut for a smaller or larger lifter.

How protein, fat, and carbohydrate are split

Protein grams are set to the body weight in pounds, which is about 2.2 grams per kilogram. That sits at the upper end of the range in the Morton protein meta-analysis, where extra protein beyond roughly 1.6 grams per kilogram stopped adding much muscle on average, with some people benefiting up toward 2.2. Fat is 25 percent of the calorie target divided by 9. Carbohydrate is whatever calories remain, divided by 4. If you change the goal offset, carbohydrate moves first because protein is tied to body weight and fat is a fixed share of calories.

Mifflin-St Jeor is one of the better resting equations for many adults, and individual errors of 10 percent are still common. People overestimate the activity word. If your average morning weight has not moved in two or three weeks, change the calorie target by a small step rather than jumping from cut to build. The paper for the equation is Mifflin and colleagues, 1990. The same form sits on the tools hub if you want the other calculators beside it.