Health & Wellbeing2 min check

Calorie Calculator

Estimate your daily maintenance calories — the energy your body needs to maintain current weight.

Short answer

BMR (Basal Metabolic Rate) is calculated using the Mifflin-St Jeor equation. Multiply by an activity factor (1.2 sedentary → 1.9 athlete) to get total daily energy expenditure (TDEE).

Step 1 of 10%

Calculation method, coverage and version

Inputs used: Sex assigned at birth, Age, Height (cm), Weight (kg), Activity level, Goal.
Calculation approach: The calculator applies the rules and assumptions described in “How it works” to the values you enter. Rounding can cause small differences from an official or provider calculation.
Coverage: Health & Wellbeing. UK nations, tax treatment, local rules and provider criteria can differ; check the official sources shown below before acting.
Content version: No page-specific review date is currently published. Treat the result as indicative and verify current rules independently.

Not included unless explicitly requested: personal circumstances not entered, provider discretion, future rule changes, professional fees and case-specific exceptions. Read the full calculator methodology.

How it works

Mifflin-St Jeor equation: for men, BMR = 10w + 6.25h − 5a + 5; for women, − 161 instead of + 5. Multiply by activity factor for TDEE.

To lose 0.5kg of fat per week, eat ~500 kcal/day below TDEE (3,500 kcal ≈ 1lb fat).

Worked example

Female, 35, 165cm, 70kg, lightly active, lose 0.5kg/week:

BMR = 10×70 + 6.25×165 − 5×35 − 161 = 1,395
TDEE = 1,395 × 1.375 = 1,918
Target: 1,918 − 500 = 1,418 kcal/day

Who should use this

•Anyone wanting a starting calorie target
•Weight-loss or weight-gain planning
•Athletes calculating fuelling needs

Common mistakes

×Overestimating activity level (most people are 'sedentary' to 'lightly active')
×Eating back exercise calories twice (TDEE already includes them)
×Cutting too aggressively — slows metabolism and loses muscle
×Forgetting drinks (especially alcohol) and 'tasters' while cooking

Frequently asked questions

How accurate is BMR?▾

Mifflin-St Jeor is the most accurate population formula but individual variation is ±10-20%.

Can I eat less than 1,200 kcal?▾

Not recommended without medical supervision — risks nutrient deficiencies and muscle loss.

Does meal timing matter?▾

For weight loss, total calories matter most. Spreading protein evenly across 3-4 meals helps muscle preservation.

Why aren't I losing weight at my deficit?▾

Common reasons: under-tracking food, overestimating activity, water retention, or adaptive thermogenesis after weeks of dieting.

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