Calorie Calculator
It estimates basal metabolic rate with the Mifflin-St Jeor equation, then multiplies by an activity factor for total daily energy expenditure.
Daily calories to maintain
2,628 kcal
Cut −20%
2,103 kcal
Maintain
2,628 kcal
Bulk +15%
3,022 kcal
Protein 30%
197 g
Carbs 40%
263 g
Fat 30%
88 g
What it calculates
It estimates basal metabolic rate with the Mifflin-St Jeor equation, then multiplies by an activity factor for total daily energy expenditure.
Why it matters
Calorie targets only work if they start from your own maintenance level. Generic 2,000 kcal advice fits almost nobody exactly.
Who it's for
Anyone planning a cut, bulk or maintenance phase, and coaches setting client intake.
Formula
- BMR
- Calories burned at complete rest
- TDEE
- BMR × activity factor
Worked example
Male, 35, 180 cm, 80 kg, moderately active
- 1BMR = 10(80) + 6.25(180) − 5(35) + 5
- 2BMR = 800 + 1125 − 175 + 5 = 1,755 kcal
- 3TDEE = 1,755 × 1.55
≈ 2,720 kcal per day to maintain weight
How the calorie calculator works
Mifflin-St Jeor: men BMR = 10w + 6.25h − 5a + 5; women BMR = 10w + 6.25h − 5a − 161, with weight in kg, height in cm and age in years. Activity multipliers run from 1.2 (sedentary) to 1.9 (very intense).
w is weight in kilograms, h is height in centimeters and a is age in years. BMR is what your body burns at complete rest.
Multiplying BMR by an activity factor gives TDEE — total daily energy expenditure. Eat below it to lose weight, above it to gain.
Common mistakes
- Overstating activity level — most desk workers who train three times a week are 'lightly active'.
- Cutting far below BMR, which is hard to sustain and costs lean mass.
- Ignoring that TDEE falls as you lose weight.
Tips and best practice
- Track weight weekly and adjust intake by 100–200 kcal based on the trend, not the formula.
- A deficit of roughly 500 kcal/day targets about 0.5 kg per week.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is what you burn at complete rest. TDEE adds movement, exercise and digestion, and is the number to base intake on.
How accurate is Mifflin-St Jeor?
It is the most accurate common predictive equation, typically within about 10% for people of average body composition.
How many calories to lose weight?
Roughly 15–20% below TDEE is a sustainable deficit for most people.
Should I eat back exercise calories?
If you already chose an activity multiplier that includes training, no — that would double count.
Related calculators
Methodology & trust
- Formula source
- Mifflin-St Jeor equation (1990).
- Last updated
- 2026-07-28
- Privacy
- Every calculation runs in your browser. No inputs are sent to a server or stored.
- Accessibility
- Keyboard navigable, labeled inputs and WCAG AA color contrast.