Calorie Calculator: Your Daily Needs by Age & Activity

What does 2,556 calories a day mean?

It means a 30-year-old man, 70 kg and 175 cm, moderately active, burns about 2,556 calories a day just living his life — 1,649 of them at complete rest, and the rest moving, working and training. Eat 2,556 and your weight holds steady; eat 2,056 and you lose roughly a pound a week; eat 3,056 and you gain roughly a pound a week. The BMR, the daily need, the loss target and the gain target are four outputs, never the same number — the BMR is what the body burns at rest, the daily need is what it burns in total, and the two targets are the daily need shifted by 500.

Three things to check before you trust the number

The activity factor is the whole game. The same man needs 1,979 calories a day sitting still and 3,133 calories a day training hard — a 1,154-calorie swing on the same body. Pick the level that matches your real week, not your best week, or the number is a wish.

Five hundred calories is roughly a pound a week. A pound of body fat holds about 3,500 calories, so 500 a day is 3,500 a week. The loss target of 2,056 and the gain target of 3,056 are the daily need moved by that much — they are a pace, not a promise, and the scale decides whether the pace is right.

The equation is an estimate, not a measurement. Mifflin-St Jeor is the most accurate of the standard equations, usually within about 10% — but muscle burns more than fat, and two people the same size can differ by hundreds of calories a day. If your weight does not move after three weeks at the target, the target is wrong for you, not the arithmetic.

Worked example

On the defaults: a 30-year-old man, 70 kg, 175 cm, moderately active.

1. BMR: 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 700 + 1,093.75 − 150 + 5 = 1,649 kcal/day (unrounded 1648.750000).
2. Daily need (TDEE): 1,649 × 1.55 = 2,556 kcal/day (unrounded 2555.562500).
3. Weight-loss target: 2,556 − 500 = 2,056 kcal/day.
4. Weight-gain target: 2,556 + 500 = 3,056 kcal/day.
5. A woman with the same numbers: 10 × 70 + 6.25 × 175 − 5 × 30 − 161 = 1,483 kcal/day (unrounded 1482.750000), daily need 2,298 kcal/day.
6. Sedentary: 1,649 × 1.2 = 1,979 kcal/day (unrounded 1978.500000) — the .5 trap: a bare Math.round in JavaScript gives 1,978.
7. Largest weight for a 2,500 daily need: 66 kg — at 66 kg the daily need is 2,494 (unrounded 2493.562500), and at 67 kg it is 2,509.
8. Smallest height for a 2,600 daily need: 180 cm — at 180 cm the daily need is 2,604, and at 179 cm it is 2,594.

Every branch, checked

• Woman, same numbers: Woman, same numbers: BMR 1,483 kcal/day; TDEE 2,298 kcal/day; lose weight 1,798 kcal/day; gain weight 2,798 kcal/day. A woman with the same numbers — BMR 1,483, daily need 2,298, 166 fewer calories a day.
• Sedentary: Sedentary: BMR 1,649 kcal/day; TDEE 1,979 kcal/day; lose weight 1,479 kcal/day; gain weight 2,479 kcal/day. Sitting still all day — daily need 1,979, loss target 1,479, and the .5 trap: 1978.5 displays as 1,979.
• Lightly active: Lightly active: BMR 1,649 kcal/day; TDEE 2,267 kcal/day; lose weight 1,767 kcal/day; gain weight 2,767 kcal/day. Light exercise 1–3 days a week — daily need 2,267.
• Very active: Very active: BMR 1,649 kcal/day; TDEE 2,844 kcal/day; lose weight 2,344 kcal/day; gain weight 3,344 kcal/day. Hard exercise 6–7 days a week — daily need 2,844.
• Extra active: Extra active: BMR 1,649 kcal/day; TDEE 3,133 kcal/day; lose weight 2,633 kcal/day; gain weight 3,633 kcal/day. A physical job plus training — daily need 3,133, nearly double the BMR.
• Age 50: Age 50: BMR 1,549 kcal/day; TDEE 2,401 kcal/day; lose weight 1,901 kcal/day; gain weight 2,901 kcal/day. Twenty years older — BMR 1,549, daily need 2,401, 155 fewer calories a day.
• Weight 90 kg: Weight 90 kg: BMR 1,849 kcal/day; TDEE 2,866 kcal/day; lose weight 2,366 kcal/day; gain weight 3,366 kcal/day. Twenty kilos heavier — BMR 1,849, daily need 2,866.
• Height 190 cm: Height 190 cm: BMR 1,743 kcal/day; TDEE 2,701 kcal/day; lose weight 2,201 kcal/day; gain weight 3,201 kcal/day. Fifteen centimetres taller — BMR 1,743, daily need 2,701.
• Age 18: Age 18: BMR 1,709 kcal/day; TDEE 2,649 kcal/day; lose weight 2,149 kcal/day; gain weight 3,149 kcal/day. Twelve years younger — BMR 1,709, daily need 2,649.
• Woman, 45, 65 kg, 160 cm, lightly active: Woman, 45, 65 kg, 160 cm, lightly active: BMR 1,264 kcal/day; TDEE 1,738 kcal/day; lose weight 1,238 kcal/day; gain weight 2,238 kcal/day. A smaller, older woman, lightly active — BMR 1,264, daily need 1,738.

The reverses, worked backwards

• Largest weight for the daily need to STAY at or below 2,500 kcal/day: 66 kg — at 66 kg the figures are BMR 1,609 kcal/day (unrounded 1608.750000); TDEE 2,494 kcal/day (unrounded 2493.562500); lose weight 1,994 kcal/day; gain weight 2,994 kcal/day; at the lower neighbor the figures are BMR 1,619 kcal/day (unrounded 1618.750000); TDEE 2,509 kcal/day (unrounded 2509.062500); lose weight 2,009 kcal/day; gain weight 3,009 kcal/day; at the upper neighbor the figures are BMR 1,599 kcal/day (unrounded 1598.750000); TDEE 2,478 kcal/day (unrounded 2478.062500); lose weight 1,978 kcal/day; gain weight 2,978 kcal/day — verdict: STEP.
• Smallest height for the daily need to REACH at least 2,600 kcal/day: 180 cm — at 180 cm the figures are BMR 1,680 kcal/day (unrounded 1680.000000); TDEE 2,604 kcal/day (unrounded 2604.000000); lose weight 2,104 kcal/day; gain weight 3,104 kcal/day; at the lower neighbor the figures are BMR 1,674 kcal/day (unrounded 1673.750000); TDEE 2,594 kcal/day (unrounded 2594.312500); lose weight 2,094 kcal/day; gain weight 3,094 kcal/day; at the upper neighbor the figures are BMR 1,686 kcal/day (unrounded 1686.250000); TDEE 2,614 kcal/day (unrounded 2613.687500); lose weight 2,114 kcal/day; gain weight 3,114 kcal/day — verdict: STEP.
• Largest age for the daily need to STAY at or above 2,400 kcal/day: 50 years — at 50 years the figures are BMR 1,549 kcal/day (unrounded 1548.750000); TDEE 2,401 kcal/day (unrounded 2400.562500); lose weight 1,901 kcal/day; gain weight 2,901 kcal/day; at the lower neighbor the figures are BMR 1,544 kcal/day (unrounded 1543.750000); TDEE 2,393 kcal/day (unrounded 2392.812500); lose weight 1,893 kcal/day; gain weight 2,893 kcal/day; at the upper neighbor the figures are BMR 1,554 kcal/day (unrounded 1553.750000); TDEE 2,408 kcal/day (unrounded 2408.312500); lose weight 1,908 kcal/day; gain weight 2,908 kcal/day — verdict: STEP.
• Smallest activity level for the daily need to REACH at least 2,800 kcal/day: Very active (1.725) — at Very active (1.725) the figures are BMR 1,649 kcal/day (unrounded 1648.750000); TDEE 2,844 kcal/day (unrounded 2844.093750); lose weight 2,344 kcal/day; gain weight 3,344 kcal/day; at the lower neighbor the figures are BMR 1,649 kcal/day (unrounded 1648.750000); TDEE 2,556 kcal/day (unrounded 2555.562500); lose weight 2,056 kcal/day; gain weight 3,056 kcal/day; at the upper neighbor the figures are BMR 1,649 kcal/day (unrounded 1648.750000); TDEE 3,133 kcal/day (unrounded 3132.625000); lose weight 2,633 kcal/day; gain weight 3,633 kcal/day — verdict: STEP.
• Smallest weight for the gain target to REACH at least 3,200 kcal/day: 80 kg — at 80 kg the figures are BMR 1,749 kcal/day (unrounded 1748.750000); TDEE 2,711 kcal/day (unrounded 2710.562500); lose weight 2,211 kcal/day; gain weight 3,211 kcal/day; at the lower neighbor the figures are BMR 1,739 kcal/day (unrounded 1738.750000); TDEE 2,695 kcal/day (unrounded 2695.062500); lose weight 2,195 kcal/day; gain weight 3,195 kcal/day; at the upper neighbor the figures are BMR 1,759 kcal/day (unrounded 1758.750000); TDEE 2,726 kcal/day (unrounded 2726.062500); lose weight 2,226 kcal/day; gain weight 3,226 kcal/day — verdict: STEP.
• Largest weight for the daily need to STAY at or below 2,000 kcal/day (30-year-old woman, 165 cm, sedentary): 94 kg — at 94 kg the figures are BMR 1,660 kcal/day (unrounded 1660.250000); TDEE 1,992 kcal/day (unrounded 1992.300000); lose weight 1,492 kcal/day; gain weight 2,492 kcal/day; at the lower neighbor the figures are BMR 1,670 kcal/day (unrounded 1670.250000); TDEE 2,004 kcal/day (unrounded 2004.300000); lose weight 1,504 kcal/day; gain weight 2,504 kcal/day; at the upper neighbor the figures are BMR 1,650 kcal/day (unrounded 1650.250000); TDEE 1,980 kcal/day (unrounded 1980.300000); lose weight 1,480 kcal/day; gain weight 2,480 kcal/day — verdict: STEP.

What the defaults assume

The defaults are a 30-year-old man, 70 kg, 175 cm, moderately active — 3 to 5 days of exercise a week, a desk job otherwise — with the Mifflin-St Jeor equation and a 500-calorie shift for losing or gaining. They are a starting point, not a benchmark: a very muscular person burns more than the equation says, a very sedentary person burns less, and the right target is the one your weight actually moves on. Change the five numbers to your own and the calculator recomputes instantly. The activity factor is the whole game — pick the level that matches your real week, not your best week.

These notes repeat in every explainer section because this page is built to be read start to finish: the defaults are one person’s numbers, not a standard; the activity factor is the whole game; 500 calories is roughly a pound a week; and the equation is an estimate, not a measurement.

Output · formula · meaning

Who uses this

• Someone starting a diet who wants the daily number to eat under — 2,056 on the defaults — instead of guessing.
• A lifter trying to gain who wants the daily number to eat over — 3,056 on the defaults — without guessing.
• A coach who sets calorie targets for clients from age, weight, height and activity, in seconds.
• A student who needs the Mifflin-St Jeor equation worked step by step for a nutrition assignment.

Accuracy & limitations

The calculator does the arithmetic exactly — the BMR is 10 times the weight plus 6.25 times the height minus 5 times the age plus 5 (men) or minus 161 (women), the daily need is the BMR times the activity factor, and the targets are the daily need shifted by 500 — and every figure on this page is checked against an independent model. What it cannot do is measure your body: Mifflin-St Jeor is usually within about 10%, but muscle burns more than fat, and two people the same size can differ by hundreds of calories a day. It also assumes the activity factor matches your real week — a desk job with a gym habit is moderate, not very active — and the 500-calorie shift is a pace, not a promise: the scale over three weeks is the real check. And the sedentary daily need is 1978.5 unrounded and displays as 1,979 — a bare Math.round in JavaScript gives 1,978 — so the page prints the unrounded figure so the rounding does not mislead you.

Cite this calculator

BMR (men) = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5; BMR (women) = 10 × weight + 6.25 × height − 5 × age − 161; daily need (TDEE) = BMR × activity factor; loss target = TDEE − 500; gain target = TDEE + 500. On the defaults — a 30-year-old man, 70 kg, 175 cm, moderately active — the BMR is 1,649 kcal/day, the daily need is 2,556 kcal/day, the loss target is 2,056 kcal/day and the gain target is 3,056 kcal/day. Largest weight for a 2,500 daily need: 66 kg. Smallest height for a 2,600 daily need: 180 cm. Largest age for a 2,400 daily need: 50 years. Smallest activity level for a 2,800 daily need: very active. Smallest weight for a 3,200 gain target: 80 kg. Largest weight for a 2,000 daily need (30-year-old woman, 165 cm, sedentary): 94 kg. Source: Bright Side Kit, brightoolbox.com.

Frequently asked questions