Calorie Calculator
See your Mifflin–St Jeor BMR formula, maintenance calories, and a live planning target in one place.
- Fewer clicks, keyboard friendly
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Mifflin–St Jeor: 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 1,649 kcal/day
TDEE = BMR × 1.55; target = TDEE × 1 = 2,556 kcal/day
These are starting estimates. Compare them with your average weight trend and adjust with a qualified professional when needed.
For adults only. Pregnancy, breastfeeding, metabolic disease, competitive training, and eating-disorder history need individual clinical guidance.
How to use
- Choose Metric or US customary units.
- Select the sex constant used by the Mifflin–St Jeor equation.
- Enter age, height, and weight, then choose your usual activity level.
- Choose a planning goal and read the BMR, maintenance, and target calories.
- Use the two visible formula lines to check how the estimate was made.
Mifflin–St Jeor BMR formula
This calculator estimates basal metabolic rate (BMR) with the Mifflin–St Jeor equation. For males it is 10 × weight in kg + 6.25 × height in cm − 5 × age in years + 5. For females it is the same expression with −161 instead of +5. The Academy of Nutrition and Dietetics Evidence Analysis Library recommends this equation using actual body weight to estimate resting metabolic rate in overweight and obese adults when indirect calorimetry is unavailable. The displayed formula substitutes your entered values so the number is inspectable rather than a hidden score. BMR is energy used at complete rest; it is not your full daily calorie need.
From BMR to maintenance calories
Maintenance calories are estimated here as BMR multiplied by a typical activity factor: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, or 1.9 extra active. The result is commonly called total daily energy expenditure (TDEE). Activity selection is usually the largest source of variation, so choose an average week rather than your best workout day. The “activity + digestion” value is simply the difference between estimated TDEE and BMR; it is not a separately measured workout total. Real expenditure changes with body size, training, sleep, illness, and everyday movement.
Use calorie targets as starting points
The loss, maintain, and gain options apply 85%, 100%, and 110% to the estimated maintenance value. They are transparent planning presets, not a diagnosis or a guarantee of weight change. Track an average trend for several weeks, because water, glycogen, menstrual cycles, and measurement error can obscure short-term changes. Recalculate after a meaningful change in body weight or usual activity. Pregnancy, breastfeeding, competitive sport, metabolic disease, and a history of disordered eating are situations where a generic equation may not fit; a clinician or registered dietitian can tailor guidance to the person and their health context.
Frequently asked questions
How does this calorie calculator calculate BMR?
This calculator uses Mifflin–St Jeor: 10 × weight in kilograms + 6.25 × height in centimetres − 5 × age, then adds 5 for males or subtracts 161 for females. The result is an estimated BMR in kcal per day.
What is the difference between BMR and TDEE?
BMR estimates the energy used at complete rest, while TDEE estimates full daily energy use after multiplying BMR by an activity factor. A sedentary factor is 1.2 and the extra-active factor in this calculator is 1.9.
How many calories should I eat to maintain my weight?
The maintenance result is an estimated TDEE, calculated as BMR times the selected activity multiplier. It is a starting estimate, so compare it with an average weight trend over several weeks before making a large adjustment.
Why does the calculator ask for sex?
The Mifflin–St Jeor equation uses a +5 constant for males and a −161 constant for females, a 166 kcal/day difference with the same age, height, and weight. The selection identifies which published equation constant is used.
Is this calorie calculator suitable for children or pregnancy?
No. This calculator is limited to adults aged 18 through 120 and is not designed for pregnancy, breastfeeding, or growing children. Those situations need age- or condition-specific assessment from a qualified health professional.
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Updated 2026-10-13