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BMR Calculator
Calories burned at rest (basal metabolic rate).
How it works
Basal metabolic rate is the energy your body needs to stay alive at rest: keeping you warm, breathing, circulating blood and repairing cells. The Mifflin-St Jeor equation estimates it from weight, height, age and sex, and it is the formula most dietitians use because it performs well across a broad adult population. It assumes a typical body composition, so very muscular or very high-fat bodies will sit somewhat above or below the estimate.
How to read the result
Your BMR is a floor, not a daily target. Real days always cost more, because even sitting upright, digesting food and walking to the kitchen add energy use. That is why a total daily figure multiplies BMR by an activity factor. Eating at or below BMR for long periods is rarely sensible without supervision: it leaves little room for activity, nutrients and recovery.
One practical tip
Use BMR to sense-check diet plans. If a plan promises far fewer calories than your BMR, treat it with suspicion and check it against your total daily expenditure instead. A sustainable plan usually sits between BMR and total expenditure for loss, or slightly above total expenditure for gain.
Remember that BMR falls slowly with age and rises with lean muscle, so strength training and adequate protein are the two most practical levers for supporting it over the years, far more than any short-term metabolic trick.
A single BMR figure also helps you spot unrealistic claims in diet advertising: any plan promising rapid loss on far fewer calories than this resting figure is almost certainly ignoring activity, muscle loss and basic nutrition needs.