What is a Calorie Calculator?
A Calorie Calculator estimates how many calories you need each day to lose, maintain or gain weight, based on your body details and activity level.
A deficit of about 500 calories a day leads to roughly 0.5 kg of loss a week. Very low intakes can be harmful, so aim for gradual change and get advice if you have a health condition.
How to use the Calorie Calculator
- Select sex.
- Enter age.
- Enter weight.
- Enter height.
- Select activity level.
- Select goal.
- Tap Calculate to see the result.
- Tap Reset to clear the fields and try again.
Who should use it
- People trying to lose or gain weight
- Anyone planning meals
- Fitness beginners
Key terms
- Maintenance calories
- Calories that keep your weight the same.
- Goal
- The rate of weight change you want.
Frequently asked questions
How many calories should I eat to lose weight?
Usually 250 to 500 below maintenance for steady loss.
Is it safe to eat very few calories?
No. Very low intake should only be done under medical supervision.
Is this medical advice?
No. Consult a doctor.
Is my data stored?
No. Everything you enter stays in your browser.
Last updated: 1 November 2026