What your numbers mean
- Maintain: about how many calories keep your weight steady with your current activity.
- Lose slowly: about 250 fewer calories a day, roughly ½ lb a week. Small changes are easier to keep up.
- Gain slowly: about 250 more calories a day.
- BMR: the energy your body uses at complete rest, for breathing, heartbeat and warmth.
How we calculate it
We use the Mifflin-St Jeor equation, one of the most widely used formulas for estimating resting calorie burn, then multiply by your activity level:
- Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
- Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Everyone's body is a little different, so treat the result as a starting point. If your weight changes differently than expected over a few weeks, adjust gently.
Gentle, steady changes
We never show weight-loss targets below 1,200 calories a day for women or 1,500 for men, because eating less than that without medical guidance isn't recommended. Pair any change with balanced meals, enough protein, and regular movement.
This is an estimate, not medical advice. It's meant for healthy adults and isn't designed for pregnancy, breastfeeding, athletes in heavy training, or anyone with a medical condition. For personal advice, talk to your doctor or a registered dietitian.
FAQ
How many calories should I eat a day?
It depends on your age, sex, height, weight and activity. Many adults need roughly 1,600–3,000 calories a day. Use the calculator for a personal estimate.
How accurate is this calorie calculator?
It's an estimate. Formulas like Mifflin-St Jeor are usually within about 10% for most people, but your real needs can differ.
Is a calorie calculator safe to use if I'm pregnant?
No. Calorie needs change during pregnancy and breastfeeding. Ask your doctor or midwife instead.