Daily Calorie Intake Calculator

Written byOleh Soloninupdated 27 September 2026

Sex

Age

Weight kg

Height cm

Activity

Goal

Result

BMR1,718
TDEE2,362
Goal Calories2,362

This result is informational only and is not professional advice.

A starting number to test, not a prescription

Estimate daily calorie needs from the Mifflin-St Jeor equation and your activity level, with targets for losing or gaining weight.

The calculation runs in two steps: your basal metabolic rate — energy used at complete rest — multiplied by an activity factor to reach total daily expenditure.

The 2005 systematic review by Frankenfield and colleagues found Mifflin-St Jeor the most reliable of the equations compared: it lands within 10 percent of measured metabolic rate more often than the others, though for one person the error can still be marked. Use the result as a starting point, then adjust against what the scale does over two or three weeks.

How to use

Choose your sex and enter your age, weight and height.
Pick an activity level. If you are torn between two, take the lower one.
Choose a goal: maintain, lose or gain weight.
The result gives your BMR, your maintenance calories and the target, with the size of the deficit or surplus.

Daily needs by activity level

BMR is multiplied by a factor from 1.2 for a sedentary life to 1.9 for hard physical work or daily training. For a 30-year-old man the gap between the two ends is about 1,200 kcal a day; for a woman of the same age, nearly 940.

Every row comes from the calculator on this page for age 30. BMR is 1,718 kcal for the man and 1,340 for the woman.
Activity	Factor	Man, 75 kg, 178 cm	Woman, 62 kg, 165 cm
Sedentary	1.2	2,061	1,608
Lightly active	1.375	2,362	1,843
Moderately active	1.55	2,662	2,077
Very active	1.725	2,963	2,312
Extremely active	1.9	3,263	2,546

Targets for losing and gaining

The calculator sets the deficit and surplus as a share of maintenance rather than one number for everyone: 15 percent to lose, 10 percent to gain. A larger person therefore gets a larger deficit — 355 kcal for the man in the example, 277 for the woman.

Lightly active, age 30; the man 75 kg and 178 cm, the woman 62 kg and 165 cm. Every row comes from the calculator on this page.
Goal	Man, kcal	Woman, kcal	Change
Maintain	2,362	1,843	—
Lose weight	2,007	1,566	−15%
Gain weight	2,598	2,027	+10%

What this calculator shows

Estimated maintenance calories for your activity level
Suggested intake for gradual loss or gain
The underlying BMR the estimate is built on

What to keep in mind

Uses the Mifflin-St Jeor equation for adults.
To lose weight the calculator takes 15 percent off maintenance; to gain, it adds 10 percent.
The activity level is your own estimate. For the man in the example, neighbouring levels differ by 300 kcal a day — almost the whole weight-loss deficit — so when in doubt choose the lower one.

Where the numbers come from

Checked against the Mifflin–St Jeor equation with activity multipliers.

FAQs

How accurate is this?

In Frankenfield's 2005 review the equation landed within 10 percent of measured resting metabolic rate more often than the others, though one person's error can still be marked. The daily figure also multiplies that rate by an activity factor you choose yourself, so its uncertainty is wider. Track your weight for two weeks and adjust from reality.

How many calories does a woman need a day?

A 30-year-old woman of 62 kg and 165 cm who is lightly active needs about 1,843 kcal to maintain her weight and 1,566 to lose it. If she is sedentary, maintenance is 1,608 kcal.

Why is my real weight loss slower than predicted?

Expenditure falls as you lose weight: in the equation every kilogram lost takes 10 kcal a day off your BMR. Food intake is also easy to underestimate. Recalculate every few kilograms.

Which activity level should I pick?

'Moderately active' means genuine training several times a week; a desk job with some walking is sedentary to lightly active. If in doubt, go lower — one level too high adds 300 kcal for the man in the example.

What calorie deficit is safe?

The calculator suggests 15 percent of maintenance — 355 kcal for the man in the example. Harvard Medical School's guidance is not to go below 1,200 kcal a day for women or 1,500 for men without medical supervision.

Is a very low calorie target a good idea?

No. Going far below your BMR costs muscle and energy and is hard to sustain. If you want to lose weight faster than a 15 percent deficit allows, talk it through with a doctor.

Worked example

A 30-year-old man, lightly active

Input: 30 years, 75 kg, 178 cm, lightly active

Output: 2,362 kcal a day to maintain

Note: His BMR is 1,718 kcal. To lose weight the calculator takes off 15 percent — 2,007 kcal, a 355 kcal daily deficit; to gain it adds 10 percent — 2,598 kcal.

Useful links

All tools in Health calculators for weight, lab values and training

Daily Calorie Intake Calculator

Result

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