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Calorie Needs Estimator

Estimate your daily calorie needs from height, weight, age, sex and activity level. See your BMR, maintenance calories, weight loss or gain targets, weekly rate estimate and personalised macro targets.

Calculator

Used in BMR equations.

Metabolic rate usually changes with age.

years

Enter your height in centimetres.

cm

Enter your current body weight.

kg

Mifflin-St Jeor is a common modern default for adults.

Only needed for Katch-McArdle.

%

This multiplier estimates total daily energy expenditure from your BMR.

Goal settings

Choose a goal and adjust the calorie change from maintenance.

kcal/day
%

Energy breakdown

Basal metabolic rate—
Activity energy estimate—
Goal adjustment—

Personalised guidance

Fat loss range
—
moderate deficit
Lean gain range
—
small surplus
Protein per meal
—
if split over 4 meals
Calorie adjustment
—
from maintenance

How the calculation works

The calculator first estimates basal metabolic rate (BMR), which is the energy your body uses at rest. The default method is Mifflin-St Jeor:

Male BMR = 10 × weight + 6.25 × height − 5 × age + 5
Female BMR = 10 × weight + 6.25 × height − 5 × age − 161

BMR is then multiplied by an activity factor to estimate maintenance calories, also called total daily energy expenditure (TDEE).

Maintenance calories = BMR × activity multiplier

Goal calories are calculated by adding or subtracting your selected daily calorie adjustment. Macro targets are estimated from body weight, protein preference, fat percentage and the remaining calories allocated to carbohydrate.

Note: Calorie calculators are estimates. Real energy needs vary due to tracking accuracy, hormones, medication, training volume, digestion, sleep, stress, menstrual cycle changes and metabolic adaptation.

How to use your calorie target

Track trends, not single days

Daily scale weight can change due to water, salt, food volume and digestion. Compare weekly averages instead.

Adjust after 2–4 weeks

If your average weight is not moving as expected, adjust calories by 100–200 kcal/day and reassess.

Prioritise protein and fibre

Protein supports muscle retention and satiety. Fibre-rich carbohydrates can help hunger, digestion and training performance.

Avoid extreme targets

Very aggressive deficits or surpluses can be hard to sustain and may affect performance, mood and adherence.

Common questions

What is the difference between BMR and TDEE?⌄
BMR is the estimated energy your body uses at rest. TDEE, or maintenance calories, includes BMR plus daily movement, exercise and activity.
How many calories should I cut for fat loss?⌄
A moderate deficit is often around 300–500 kcal/day. Larger deficits can work but may be harder to maintain.
How many calories should I add for muscle gain?⌄
A small surplus of around 150–300 kcal/day is often enough for lean gaining. Larger surpluses may increase body fat gain.
Are macro targets required?⌄
No. Total calories drive weight change, but macros can improve satiety, training performance and muscle retention.

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