OmniCalcsCalorie Calculator
Estimate how many calories you burn each day — and how many to eat to lose, gain, or maintain weight.
How to Use This Calorie Calculator
Enter your stats and activity level. The result is the number of calories needed to hold your weight steady. From there:
- To lose weight — eat roughly 500 kcal less per day to lose about 0.45 kg (1 lb) per week.
- To gain weight — eat 250-500 kcal above maintenance while training to build muscle.
- Reassess monthly — as your weight changes, so does your maintenance number.
Frequently Asked Questions
How accurate is the Mifflin-St Jeor equation?
It is one of the most accurate BMR equations, usually within 5-10% of measured values for healthy adults.
Why did my calories change after I lost weight?
A smaller body burns fewer calories. Recalculate after every ~5 kg (10 lb) of change to keep targets realistic.
Are all calories the same?
For weight math, roughly yes. For health, no — 2,000 kcal of vegetables and protein is very different from 2,000 kcal of sugar.
Is this medical advice?
No. These are estimates for healthy adults. Pregnant women, athletes and people with medical conditions should consult a professional.
Practical Example
A 32-year-old, 70 kg, 175 cm man who exercises 3–5 days a week:
- BMR (Mifflin-St Jeor) ≈ 1,675 kcal/day
- Maintenance calories ≈ 2,600 kcal/day (moderate activity)
- To lose ~0.5 kg/week, aim for ≈ 2,100 kcal/day
- To gain muscle slowly, target ≈ 2,850 kcal/day
What Your Results Mean
- BMR — calories your body burns at complete rest, before any activity.
- Maintenance — calories to keep your weight stable at your activity level.
- Deficit/surplus — eating below maintenance loses weight; above it gains weight.