Maintenance Calorie Calculator

Background.

Maintenance calories are the daily energy intake at which your weight holds steady — consumption matching expenditure. Estimating that number is a two-step calculation with a long research pedigree: first the energy your body burns at complete rest, then a multiplier for how active your life actually is.

The resting piece uses the Mifflin-St Jeor equation, published in 1990 from indirect-calorimetry measurements and since endorsed by the Academy of Nutrition and Dietetics as the most accurate of the common predictive formulas for healthy adults — typically within about 10% of measured resting expenditure. It reads BMR = 10·weight(kg) + 6.25·height(cm) − 5·age(years) + 5 for males, with −161 replacing +5 for females — heavier and taller bodies burn more, each year of age trims about 5 kcal/day, and the sex constant reflects average body-composition differences.

The activity multiplier then scales resting burn to a whole life: 1.2 for sedentary desk-bound days, 1.375 for light exercise a few times weekly, 1.55 for moderate training most days, 1.725 for hard daily training, 1.9 for heavy physical work or double sessions. Choosing honestly is the step that decides the estimate's usefulness — self-rated activity runs notoriously optimistic, and one level too high adds several hundred phantom calories.

The result is a starting estimate for a healthy adult, not a measurement: individual metabolisms scatter around every equation, and pregnancy, illness, and athletic periodisation sit outside the model, as the scope note says. The practical use is calibration — eat near the estimate for two or three weeks, watch the scale's weekly average, and adjust by 100–200 kcal at a time. Your own trend data beats any formula.

What is maintenance calorie calculator?

Maintenance calories (total daily energy expenditure, TDEE) are the calories per day at which energy in equals energy out and body weight stays level. This page estimates them as Mifflin-St Jeor BMR × activity factor. The BMR term — 10·kg + 6.25·cm − 5·years, plus 5 (male) or minus 161 (female) — predicts resting energy burn, the majority component of TDEE for most people; the factor (1.2–1.9) folds in occupational movement, exercise, and daily activity. Eating consistently below the maintenance level produces weight loss, above it gain, at roughly 7,700 kcal per kilogram of body-weight change.

How to use this calculator.

1. 01Select the sex used by the equation and enter age in years, height in centimetres, and weight in kilograms — the units the coefficients were fitted in.
2. 02Pick the activity factor honestly, counting only what you actually do in a typical week: 1.2 sedentary, 1.375 light (1–3 sessions/week), 1.55 moderate (most days), 1.725 hard daily training, 1.9 physical labour or twice-daily training.
3. 03Read both outputs: the BMR line is your estimated resting burn; the maintenance line is the full daily estimate.
4. 04Treat the maintenance figure as a hypothesis: hold intake near it for 2–3 weeks, compare weekly-average weights, and nudge by 100–200 kcal until the trend flattens — that calibrated number supersedes the formula.
5. 05Recompute after meaningful change — every 5 kg gained or lost, or a genuine shift in training or job activity — since both terms of the product move with you.

The formula.

The Mifflin-St Jeor coefficients are regression estimates from measured resting metabolism in about 500 adults: each kilogram of body mass adds ≈10 kcal/day of resting burn (tissue costs energy to run), each centimetre of height ≈6.25 (taller frames carry more lean mass at a given weight), each year of age subtracts ≈5 (lean mass and cellular activity decline slowly), and the sex constant (+5 vs −161) captures average male-female body-composition differences at identical size — about 166 kcal/day. Multiplying by the activity factor implements the standard physical-activity-level framework: total expenditure is expressed as a multiple of resting, from ≈1.2 for bed-to-desk living to ≈1.9 at the limits of sustained human activity. Both terms are population averages — individual BMRs scatter roughly ±10% around the prediction (genetics, thyroid status, lean-mass fraction), and activity factors are self-assessed — so the product is a well-founded starting point with honest error bars, refined only by observed weight trend. The engine evaluates the linear form and product in Decimal arithmetic, rounding once at the output.

A worked example.

Frequently asked questions.

References& sources.

1. [1]Mifflin et al.. American Journal of Clinical Nutrition 1990. Resting energy expenditure prediction equation. Retrieved 2026-08-06. independence: primary; access: open.
2. [2]U.S. National Institutes of Health. Health information current 2026. Evidence-based health measurement context. Retrieved 2026-08-06. independence: secondary-check; access: open.
3. [3]U.S. National Library of Medicine. PubMed record current 2026-08-06. Indexed derivation and validation literature. Retrieved 2026-08-06. independence: primary; access: open.