Calorie Calculator
Estimate how many calories you burn each day and how many to eat to keep, lose or gain weight, using the Mifflin-St Jeor formula.
To keep your weight
2,220 calories a day
- To lose about 0.5 kg a week
- 1,720 a day
- To gain about 0.5 kg a week
- 2,720 a day
- At complete rest (BMR)
- 1,620 a day
You burn about 2,220 calories a day. Eating around 1,720 a day would lose roughly half a kilo a week.
How it's worked out
- Resting energy (Mifflin-St Jeor)
10 × 70 + 6.25 × 170 − 5 × 30 + 51,618 kcal - Times your activity level
1,618 × 1.3752,224 kcal - Weight change
about 500 kcal a day below or above, for roughly 0.5 kg a week1,720 / 2,720 kcal
- An estimate: real needs vary by about 10% either way. Watch your weight for 2 to 3 weeks and adjust.
- Targets never go below 1,500 calories a day without medical advice.
The formula
Resting energy = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 (men) or − 161 (women)
Worked example
A 30-year-old man of 70 kg and 170 cm burns about 700 + 1,062.5 − 150 + 5 = 1,617.5 calories at rest. Moderately active (× 1.55), that's about 2,510 a day to keep his weight.
Questions people ask
How many calories do I need a day?
It depends on your size, age, sex and activity. The calculator estimates your resting energy with the Mifflin-St Jeor formula and multiplies it by your activity level.
How many calories should I cut to lose weight?
About 500 a day below your maintenance level loses roughly 0.5 kg a week for most people. Bigger cuts are harder to keep up and can cost muscle.
Why Mifflin-St Jeor?
Studies comparing the common formulas found it the most accurate for most adults, which is why dietitians widely use it.
About this calculator
Formula and rules last checked 25 October 2026Written and tested by the CalcPenguin teamReport a problem
Sources: Mifflin et al. (1990), American Journal of Clinical Nutrition