Useful Utilities

Calorie Calculator

Estimate your daily calorie needs in kcal/day: basal metabolic rate by both Mifflin–St Jeor and Harris–Benedict formulas, maintenance and deficit targets scaled by activity multipliers (x1.0 to x1.8).

Fill in the values and calculate

SexBoth basal formulas split by sexDefault Male
Age (years)*Age at last birthday — required
Height (cm) (cm)Height in centimetres, shoes offDefault 170
Weight (kg) (kg)Current weight in kilogramsDefault 70
Activity levelJudge real sessions per weekDefault Moderately active (×1.4)

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About Calorie Calculator

The Calorie Calculator turns body facts into daily energy needs in two steps. First basal metabolic rate (BMR) — the energy an idle body would turn over at rest — is estimated by two published formulas: the Mifflin–St Jeor equation (10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for men, the same terms with − 161 for women) and the original Harris–Benedict equations (men: 66.5 + 13.75 × weight + 5.003 × height − 6.75 × age; women: 655.1 + 9.563 × weight + 1.85 × height − 4.676 × age), both with weight in kilograms and height in centimetres. Second, that basal rate is scaled by an activity factor. This page deliberately uses the classic Harris additions of +0/+20/+40/+60/+80% (×1.0 sedentary, ×1.2 lightly active, ×1.4 moderately active, ×1.6 very active, ×1.8 extremely active); the popular modern scheme (×1.2–×1.9) lives on the TDEE page — neither is measurably better, they are different published schemes, and honest choice matters more than the factor itself.

The maintenance figure is what an average day out burns: eat at it and weight stays stable. Against it, the page shows deficit targets of −250 kcal/day (gentle) and −500 kcal/day (aggressive), and an intake floor around BMR × 1.2 — going below basal metabolic rate means eating less than the body uses even at rest, so a large gap is better split with activity than taken from food. Weight change converts at the site's convention of 7,700 kcal ≈ 1 kg (3,500 kcal ≈ 1 lb) of tissue.

These are models, not measurements: Mifflin–St Jeor was fitted to adults from about 19 upward, the Harris equations to ages 20–70, and both carry a few percent of individual error before behaviour. Measured trackers (heart-rate monitors, METs tables on the calorie-burn page) give per-session answers instead; use those for training days and this figure for an ordinary week.

Questions about Calorie Calculator

Why show two BMR numbers that disagree?

Because the two published formulas genuinely disagree — same inputs can differ by tens of kcal/day. Showing both is the honest way to state a range; the note reports the gap explicitly so you see which formula you are leaning on.

Are the ×1.0–×1.8 factors the ones other sites use?

No. Modern sites popularize ×1.2–×1.9; these are the original Harris activity additions (+0/+20/+40/+60/+80%). This page uses them so the BMR and the activity scaling come from the same published source. The TDEE calculator on this site runs the modern scheme.

Is a 500 kcal/day deficit safe?

Usually yes: about 3,500 kcal a week ≈ 1 lb (0.45 kg) of tissue a week. The check is the floor — as long as the food target stays above basal metabolic rate, the body is not being asked to eat less than it uses even at rest.

Does activity level mean my workout calories?

It describes the whole-day average state (sitting hours included), not the workout alone. A 40-minute run does not make a desk worker 'moderate'; judge sessions per week honestly. See the calorie-burn calculator for per-session figures.

What if the aggressive target falls below my BMR?

The note flags it: below basal rate, more food cuts than the model can stand usually mean the real lever is activity, not food. The floor card shows the level where you keep eating at least basal-plus-twenty-percent.

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