Calorie Calculator: How Many Calories Do I Need?
Your daily calorie need is your basal metabolic rate (BMR) multiplied by an activity factor. For a 30-year-old man who is 180 cm, weighs 80 kg and exercises 3 to 5 days a week, that is about 2,760 calories a day.
Maintenance calories
1,996 kcal/day
Resting (BMR)
1,452 kcal/day
Daily calories for your goal
- Faster loss (−500)1,496 kcal
about 0.5 kg (1 lb) per week
- Gentle loss (−250)1,746 kcal
about 0.25 kg (½ lb) per week
- Maintain weight1,996 kcal
stay at your current weight
- Gentle gain (+250)2,246 kcal
about 0.25 kg (½ lb) per week
- Faster gain (+500)2,496 kcal
about 0.5 kg (1 lb) per week
An estimate, typically within about 10% of real needs. Not suitable if you are pregnant, breastfeeding, under 18 or have a medical condition. Speak to a doctor or dietitian first.
Show the math
- 1
Work out your basal metabolic rate (BMR)
10 × 70 + 6.25 × 170 − 5 × 30 − 161 = 1,452
This is the Mifflin-St Jeor equation. BMR is the energy your body burns at complete rest to keep you alive.
= 1,452 kcal
Read the steps as text
- Work out your basal metabolic rate (BMR). 10 × 70 + 6.25 × 170 − 5 × 30 − 161 = 1,452 This is the Mifflin-St Jeor equation. BMR is the energy your body burns at complete rest to keep you alive.
- Multiply by your activity level. 1,452 × 1.375 (lightly active) = 1,996 Movement and exercise add to the energy you use each day. The result is your total daily energy expenditure (TDEE).
- Adjust for your goal. Lose: 1,996 − 500 = 1,496 · Gain: 1,996 + 500 = 2,496 About 7,700 calories equals 1 kg of body weight, so a daily change of 500 calories is roughly 0.5 kg a week.
How your calories are calculated
The calculator uses the Mifflin-St Jeor equation, one of the most widely used formulas for estimating resting energy use. BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age, then plus 5 for men or minus 161 for women. BMR is the energy your body burns at rest to breathe, circulate blood and keep warm.
Your total daily energy expenditure (TDEE) adds the energy you spend moving. BMR is multiplied by an activity factor: 1.2 for a sedentary lifestyle, 1.375 for light exercise, 1.55 for moderate exercise, 1.725 for hard exercise most days and 1.9 for very hard exercise or a physical job. The result is your maintenance calories, the amount that keeps your weight steady.
Calories for losing or gaining weight
Roughly 7,700 calories is equivalent to 1 kg of body weight, so eating about 500 calories a day below maintenance leads to around 0.5 kg (1 lb) of loss a week, and 500 above leads to a similar gain. The chart shows five goals, from a gentle 250 calorie change to a faster 500.
These are averages. Real progress varies with your body, sleep, the type of weight gained or lost, and how your metabolism adapts over time. Very low calorie intakes are not advised without medical supervision, so targets below about 1,200 calories for women or 1,500 for men are flagged.
Choosing your activity level
Pick the level that matches a typical week, not your best week. Most people who sit at a desk and exercise a few times a week fit best in lightly or moderately active. Overestimating activity is the most common reason results seem too generous, so if in doubt, choose the lower level and adjust after a few weeks of tracking your weight.
Frequently asked questions
- What is the difference between BMR and TDEE?
- BMR is the calories you burn at complete rest. TDEE is BMR plus the calories you use through movement and exercise, so it is the number that matters for daily eating.
- How many calories should I eat to lose weight?
- A common starting point is 250 to 500 calories below your maintenance level, which is about 0.25 to 0.5 kg (0.5 to 1 lb) a week. Avoid going below about 1,200 calories (women) or 1,500 calories (men) without medical advice.
- How accurate is this calculator?
- It is an estimate that is usually within about 10% of real needs. Track your weight for two to three weeks and adjust if it is not moving the way you expect.
- Why does the calculator ask for sex?
- The Mifflin-St Jeor equation has a different constant for men and women because average body composition differs. Use whichever is closest to your body, and treat the result as an estimate.