Calorie calculator
Estimate the energy an adult may use in a day from height, weight, age and activity. This is a maintenance estimate to discuss with a clinician or dietitian, not a personalised eating target.
How the estimate works #
The Mifflin–St Jeor equation estimates resting energy expenditure: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), then +5 for the male equation or −161 for the female equation. We multiply by the selected activity factor (1.2, 1.375, 1.55 or 1.725) to estimate maintenance energy.
These equations and activity categories are estimates. Body composition, illness, medicines and activity can change your needs. No fixed calorie deficit or rate of weight loss is prescribed by this calculator.
If you are on GLP-1 treatment #
If treatment reduces your appetite, you still need enough energy, fluids and nutrients. Do not treat the estimate as a ceiling or try to eat as little as possible. A clinician or registered dietitian can help you plan an adequate intake and adjust it to your health and treatment.
Read the protein guide for questions to discuss about maintaining muscle.
When to ignore the number #
This tool is not suitable for children, pregnancy, breastfeeding or managing an eating disorder. Seek individual advice if you have an illness affecting your nutritional needs. Persistent dizziness, weakness or difficulty eating enough should be discussed with a healthcare professional.
Low-energy diets require appropriate support; see NICE guidance on dietary approaches.
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Page information
- Summary
- Estimate adult daily maintenance energy using the Mifflin–St Jeor equation. See the calculation, limitations and when to seek individual advice.
- Publisher
- Aero Clinic, operated by AERO HEALTHCARE LTD.
- Editorial update
- Clinical review
- Pending. An editorial update is not a clinical sign-off.
Cite as: Calorie calculator, Aero Clinic (https://www.cagri.co.uk), AERO HEALTHCARE LTD. https://www.cagri.co.uk/calorie-calculator. Editorial update: 4 November 2026. Clinical review pending.