Calorie Calculator

Your inputs

Mifflin–St Jeor resting-energy estimate × selected activity multiplier. Adults only; not for pregnancy, breastfeeding, eating-disorder treatment or medical nutrition planning. This is not a prescribed intake. Goal targets use the standard basis that about 0.5 kg of body weight per week ≈ a 550 kcal daily difference; macros split the maintenance figure at 4 kcal per gram of protein or carbohydrate and 9 kcal per gram of fat.

Live results

Auto-updates

Estimate adult resting energy and daily maintenance needs with metric or US measurements — plus goal targets for losing or gaining about half a kilo a week, and a protein, carbohydrate and fat split in grams at a ratio you choose.

100% free · No sign-up · No daily limits · No watermarks · Processed in your browser — files never leave your device

UNDERSTAND YOUR RESULTS

Calorie Calculator guide

Estimate adult resting energy and daily maintenance needs with metric or US measurements — plus goal targets for losing or gaining about half a kilo a week, and a protein, carbohydrate and fat split in grams at a ratio you choose.

How to use this tool

Enter Age (18–80 years), Equation sex coefficient, Measurements, Height (cm, or total inches for US), Weight (kg, or pounds for US), Activity assumption, Macro split (protein / carbs / fat).
Change a value to update the results and illustration. Check any validation message before using the output.
Copy the results or download CSV. Reset restores the example values.

A worked example

For age 30, male coefficient, 175 cm, 70 kg and a 1.2 activity multiplier: resting energy = 1,648.75 kcal/day; estimated maintenance = 1,978.5 kcal/day. The goal rows sit 550 kcal either side of maintenance — about 1,428.5 kcal/day to lose roughly 0.5 kg a week, 2,528.5 to gain it — and the balanced 30/40/30 macro split turns maintenance into about 148 g protein, 198 g carbohydrate and 66 g fat a day. Rounded display values are not a precise nutritional requirement.

What you can do with this tool

Enter age (18–80 years), height and weight in metric (cm, kg) or US measurements (total inches, pounds).
Set the equation sex coefficient and your activity assumption.
Estimate your resting energy and daily maintenance calories.
See goal targets for losing or gaining about half a kilo a week, 550 kcal either side of maintenance.
Choose a macro split (protein / carbs / fat) and get the split in grams at the ratio you choose.
Copy the results or download them as CSV.
Reset to restore the example values.

How it works

Mifflin–St Jeor resting-energy estimate × selected activity multiplier. Adults only; not for pregnancy, breastfeeding, eating-disorder treatment or medical nutrition planning. This is not a prescribed intake. Goal targets use the standard basis that about 0.5 kg of body weight per week ≈ a 550 kcal daily difference; macros split the maintenance figure at 4 kcal per gram of protein or carbohydrate and 9 kcal per gram of fat.

The equation behind the estimate

Resting energy (kcal/day) = 10 × weight in kg + 6.25 × height in cm − 5 × age in years + coefficient. The male coefficient is +5; the female coefficient is −161. Estimated maintenance = resting energy × your selected activity multiplier. Kilojoules = kcal × 4.184.

Activity labels are broad assumptions. Small input differences and day-to-day variation change the result; this is not a measurement of metabolism. It does not account for pregnancy, breastfeeding, illness, medications or individual body composition.

Sources: Original Mifflin–St Jeor study and NIDDK adult-use limitations and Body Weight Planner.

Frequently asked questions

Is this an exact calorie target?

No. It combines a population-based resting-energy equation with a chosen activity multiplier. Actual energy needs vary, and the multiplier is an assumption, not a measurement.

Who should not use it for meal planning?

Children, pregnant or breastfeeding people, and people needing clinical nutrition or eating-disorder support should use individualized professional guidance instead.

Why does the equation ask for a sex coefficient?

The published equation has two statistical coefficients. They do not account for individual body composition or every person’s physiology; discuss an appropriate approach with a clinician if uncertain.

Does switching units convert my existing entries?

No. Re-enter height and weight in the selected units. US height is total inches, not feet.

Blog · Shop · About · Contact · Privacy Policy · Terms