Calorie calculator
Enter your age, height, weight and usual activity to estimate your BMR and the calories you burn in a day. For adults.
Worked example: age 30, 170 cm, 65 kg
Calculated with the same formula as the calculator. Maintenance calories are rounded to the nearest 10 kcal.
Worked example: age 30, 170 cm, 65 kg| Activity | Man (kcal) | Woman (kcal) |
|---|
| BMR (resting) | 1,568 | 1,402 |
|---|
| Sedentary (×1.2) | 1,880 | 1,680 |
|---|
| Light (×1.375) | 2,160 | 1,930 |
|---|
| Moderate (×1.55) | 2,430 | 2,170 |
|---|
| Very active (×1.725) | 2,700 | 2,420 |
|---|
| Extra active (×1.9) | 2,980 | 2,660 |
|---|
Imperial example: woman, 35, 5 ft 5 in, 150 lb
5 ft 5 in = 165.1 cm, 150 lb = 68.0 kg. BMR = 10 × 68.04 + 6.25 × 165.1 − 5 × 35 − 161 ≈ 1,376 kcal. Maintenance: about 1,650 kcal a day if sedentary, 2,130 kcal with exercise 3-5 days a week.
How the calculation works
First the calculator estimates your resting energy expenditure, the energy you use lying still, with the Mifflin-St Jeor equation. It was built in 1990 from measurements of 498 healthy adults.
Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
That number is multiplied by an activity factor from 1.2 to 1.9 to estimate total daily energy expenditure (TDEE): the calories that keep your weight where it is. Pounds and inches are converted to kilograms and centimetres first. One kilocalorie is 4.184 kilojoules.
Choosing your activity level
If you are unsure, pick the lower option. Choosing a higher level than your real routine is the most common way to overestimate calorie needs. A job that keeps you on your feet or does heavy lifting can justify a higher level even without workouts. The factors are a common approximation used with this equation; they do not come from the original study.
How accurate is it?
A 2005 systematic review of the four most used equations found that Mifflin-St Jeor came within 10% of measured resting metabolic rate for more people than the others, with the narrowest error range. Some individuals still miss by more, and older adults and several ethnic groups were under-represented in the research. Very muscular or very lean bodies can also differ from the formula.
Treat the result as a starting point. Keep intake steady for two to three weeks, watch your weight trend and adjust in small steps. As you lose weight your needs fall too, so the same intake gradually produces slower change.
FAQ
What is the difference between BMR and TDEE?
BMR is the energy you use at rest. TDEE adds everything else in your day: walking, work, exercise and digesting food. This calculator estimates TDEE by multiplying BMR by an activity factor.
How many calories does a 30-year-old man at 170 cm and 65 kg need?
His BMR is about 1,568 kcal. To maintain weight he needs about 1,880 kcal a day if sedentary, or about 2,430 kcal with exercise 3-5 days a week.
How fast will I lose weight eating 500 kcal less a day?
It varies, and it slows over time. Early loss includes water, and as you get lighter you burn fewer calories, so the same deficit shrinks. Use your weight trend over several weeks to adjust.
Is it safe to eat below my BMR?
The result table flags any target below your BMR. Large cuts make it hard to get enough nutrients, so plan them with a doctor or registered dietitian rather than on your own.
Where are my inputs stored?
Everything is calculated in your browser and nothing is sent to a server. Only your last inputs are saved in this browser so they are there next time.
