Use this independent UK calorie calculator to estimate your daily calorie needs for maintenance and to see an indicative weight-loss target. It uses the Mifflin-St Jeor resting-energy equation plus an activity multiplier. It is not an official NHS calculator and the result is an estimate rather than a personalised diet prescription.
Daily calorie needs calculator
What does this calorie calculator estimate?
The calculator estimates your resting energy requirement (BMR) from age, sex, height and weight, then applies an activity factor to estimate maintenance calories. NHS guidance gives broad averages of about 2,500 kcal a day for an average man and 2,000 kcal for an average woman, while noting that individual needs vary.
How the calculation works
The resting-energy estimate uses the Mifflin-St Jeor equation published in 1990. For men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5. For women, the final constant is −161. The calculator then multiplies BMR by the selected activity factor to estimate total daily energy expenditure.
Activity factors used
| Activity level | Factor |
|---|---|
| Sedentary | 1.2 |
| Lightly active | 1.375 |
| Moderately active | 1.55 |
| Very active | 1.725 |
| Extra active | 1.9 |
Worked example
A 30-year-old man who is 180 cm tall and weighs 80 kg has an estimated BMR of 1,780 kcal/day with this equation. Selecting moderately active applies a factor of 1.55, producing an estimated maintenance requirement of about 2,759 kcal/day. A simple 600 kcal reduction would display about 2,159 kcal/day as an indicative weight-loss figure.
Calories for weight loss
NHS Better Health says that people trying to lose weight can aim to reduce their intake by around 600 calories a day. That is general population guidance, not a personalised prescription. Your appropriate intake can differ because of health conditions, pregnancy, medicines, body composition, activity and other factors.
Important limitations
- This tool is designed for adults and is not intended for children or pregnancy.
- BMR and activity factors are estimates; actual energy expenditure can differ.
- Do not use the result to plan a very restrictive diet.
- Speak to a GP, dietitian or other qualified healthcare professional before significant dietary changes if you have a medical condition, a special therapeutic diet, an eating disorder or a history of disordered eating.
Authoritative sources
- NHS: Understanding calories
- NHS Better Health: Calories and weight loss
- Mifflin et al. resting energy equation
Related calculators
- NHS Calculator
- TDEE Calculator NHS
- Calorie Deficit Calculator NHS
- BMR Calculator NHS
- BMI Calculator NHS
- How Much Weight Have I Lost Calculator NHS
- How Many Steps to Lose Weight Calculator NHS
Frequently asked questions
Is this an official NHS calorie calculator?
No. This is an independent UK calculator that references NHS calorie guidance. The Mifflin-St Jeor equation is not an NHS formula.
How many calories does the NHS recommend?
As a broad guide, the NHS says an average man needs around 2,500 kcal a day and an average woman around 2,000 kcal a day, but individual needs can vary.
How many calories should I eat to lose weight?
NHS Better Health gives general guidance to reduce intake by around 600 kcal a day for weight loss. A calculator cannot determine whether that target is appropriate for your personal circumstances.
What is the difference between BMR and maintenance calories?
BMR estimates energy used at rest. Maintenance calories estimate total daily needs after an activity factor is applied.
Independent informational tool only. It does not provide medical or dietary advice and is not affiliated with or endorsed by the NHS.