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Calorie calculators: know the formula, not just the number.

Twelve calorie and fitness calculators, each named to the equation behind it: Mifflin-St Jeor for energy needs, the U.S. Navy circumference method for body fat, CDC ranges for BMI. Enter your numbers and see the math a dietitian would recognize, not a black box.

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Calorie & Fitness Calculators

Everything you need to plan your nutrition and training.

Every result names its source.

The BMR and TDEE calculators run the Mifflin-St Jeor equation, published in the American Journal of Clinical Nutrition in 1990. Body fat uses the U.S. Navy circumference method from a 1984 Naval Health Research Center report. BMI uses the same weight-over-height-squared formula and category cutoffs the CDC publishes. Protein targets follow the range in the International Society of Sports Nutrition's 2017 position stand, not a made-up round number. The full source list is on the editorial standards page, and every calculator links back to it.

Why this instead of a generic calorie site

Three things most calorie calculators skip

A formula you can name

Search "calorie calculator" and most results give you a number with no citation. The TDEE and BMR calculators here tell you which published equation ran, so you can check it against a textbook or a dietitian's own math.

Limits stated up front

The BMI calculator and body fat calculator both say plainly what their formulas can't see, mainly muscle mass, instead of presenting a single number as a verdict on your health.

Guides that show the arithmetic

Pages like what is TDEE and how to count macros walk the math by hand, so you can check a calculator's output yourself instead of taking our word for it.