Calorie Calculator
Estimate your daily calories, BMR and maintenance level using UK-friendly units, then choose a sensible target for maintenance, weight loss or weight gain.
Calculate your daily calories
Enter your details to estimate your BMR, daily maintenance calories and a goal-based calorie target.
This is your estimated daily calorie target for the selected goal.
How this calorie calculator works
This calculator estimates your basal metabolic rate first, then multiplies it by an activity factor to estimate your TDEE. That gives a starting point for your daily maintenance calories.
The result is useful for planning, but it is not exact. Daily movement, muscle mass, hormones, sleep, stress, health conditions and food-tracking accuracy can all change the real number.
Calorie calculator formula
The calculator uses the Mifflin-St Jeor equation for BMR, then applies an activity multiplier.
Male BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5
Female BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161
Maintenance calories = BMR × activity factorGoal targets are then adjusted from maintenance: maintain stays the same, slow loss subtracts 300 kcal, general loss subtracts 600 kcal, and gradual gain adds 300 kcal.
How to read your calorie result
| Output | What it means |
|---|---|
| BMR | Your estimated calories at rest before normal activity is added. |
| Maintenance calories | Your estimated daily calories to maintain current weight at your selected activity level. |
| Target calories | Your estimated daily target after applying the selected goal adjustment. |
For weight loss, the calculator creates a calorie deficit. For weight gain, it creates a surplus. Neither guarantees a specific weekly change because bodies adapt and real intake is hard to measure perfectly.
Choosing a sensible calorie target
A smaller calorie change is often easier to sustain than a very aggressive one. NHS Better Health suggests reducing intake by around 600 calories a day as a safe and sustainable approach for many adults, but that does not mean every adult should use the same target.
If the calculator gives a very low number, use caution. Do not follow very restrictive diets without qualified support, especially if you are pregnant, breastfeeding, under 18, have a medical condition, or have a history of disordered eating.
Worked calorie examples
Calorie calculator FAQs
Is this calorie calculator accurate?
It is a useful estimate, not a precise measurement. It cannot know your body composition, daily movement, health history, digestion, hormones or how accurately food intake is tracked.
What is the difference between BMR and TDEE?
BMR estimates calories used at rest. TDEE estimates total daily calories after activity is added.
Should I use the 600 calorie deficit option?
Not automatically. It can be a common general starting point for many adults, but a smaller change may be more suitable depending on your body size, health, routine and support.
Can I use this calculator while pregnant?
No. Pregnancy changes energy needs and weight guidance. Speak to a midwife, GP or qualified health professional instead.
Related glossary terms
These terms help explain the numbers used by this calculator.
Build a fuller picture
Calories are one part of health and body composition. Compare your result with BMI, body fat, macros and protein estimates before making big changes.
Calculatorz may earn a commission from some partner links. Health calculator results are estimates only and not medical advice.