Enter your age, sex, height, weight and activity level to get your basal metabolic rate and the daily calories needed to maintain, lose or gain weight.
How to use this calculator
Choose your units, then enter your sex, age, height and weight.
Pick the activity level that matches an honest weekly average — most office workers with 2–3 workouts are 'light' or 'moderate'.
Read your BMR (calories burned at complete rest) and your maintenance calories (TDEE).
Use the loss or gain targets: ±500 kcal per day shifts weight by about 0.5 kg (1 lb) per week.
Recalculate after every ~5 kg change or when your training volume changes — needs move with your body.
s = +5 for males, −161 for females. Activity multipliers: sedentary 1.2 · light 1.375 · moderate 1.55 · active 1.725 · very active 1.9. A ±500 kcal/day change shifts weight by roughly 0.5 kg (1 lb) per week.
Example
A 30-year-old male, 175 cm and 70 kg: BMR = 10×70 + 6.25×175 − 5×30 + 5 = 1,649 kcal. Moderately active → TDEE ≈ 1,649 × 1.55 ≈ 2,556 kcal/day.
Key insights
At the same height and weight, BMR drops roughly 50 kcal/day per decade of age in the Mifflin-St Jeor equation.
Activity multipliers span 1.2 to 1.9 — a very active person can need over 50% more calories than a sedentary one of the same size.
A steady 500 kcal/day deficit targets about 0.5 kg (1 lb) of loss per week, based on ≈3,500 kcal per 0.45 kg of body fat.
Overestimating your activity level is the most common reason calculated calorie targets 'don't work'.
Eating below your BMR for extended periods is not recommended without medical supervision.
How to interpret your result
Maintenance (TDEE)
Eat at this level and your weight should stay roughly stable. It already includes your workouts — do not add exercise calories on top.
Choosing a deficit
Sustainable fat loss is about 0.25–1% of body weight per week. Larger deficits cost muscle, energy and adherence.
Choosing a surplus
For muscle gain, +250–500 kcal/day combined with resistance training beats bigger surpluses, which mostly add fat.
It is an estimate
Real needs vary by ±10% or more. Track your weight for 2–3 weeks and adjust intake by 100–200 kcal rather than trusting a single number.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is what your body burns at complete rest just to stay alive. TDEE (total daily energy expenditure) adds movement and exercise — it is the number to eat at to maintain your current weight.
How accurate is the Mifflin-St Jeor formula?
It is the equation recommended by the American Dietetic Association and typically lands within ±10% for most adults. Muscle mass, genetics and medical conditions can shift your real needs.
Is a 500-calorie deficit safe?
For most adults, yes — it targets about 0.5 kg (1 lb) of loss per week. Avoid eating below your BMR for extended periods without medical supervision.
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Percentage Calculator — Find X% of a number, what percent X is of Y, or the change between two values.