Calorie Calculator
Find daily calories for your goal.
kg or lb
cm or in
Results update as you type.
This calculator provides estimates based on population research. Results are not medical advice. Consult a qualified healthcare provider before making health or nutrition decisions.
How it works
A daily calorie target is the amount of energy you aim to eat to reach a specific goal, whether that is losing fat, holding your weight steady or gaining mass. It rests on the principle of energy balance: eat fewer calories than you burn and stored fat is used for fuel, eat more and the surplus is banked as new tissue. This calorie calculator first works out your Total Daily Energy Expenditure, deriving basal metabolism from the Mifflin-St Jeor equation, a formula validated against measured resting metabolism by indirect calorimetry, and scaling it by your activity level. It then applies your goal as an adjustment. A shortfall of roughly 500 kcal per day tends to yield about 0.5 kg of fat loss per week, because a kilogram of body fat stores close to 7,700 kcal, while a matching surplus supports steady gain. Dietitians, personal trainers and people managing their weight use a calorie calculator to turn a vague intention into a concrete daily number they can plan meals around. The Mifflin-St Jeor basis is why this calorie calculator is more reliable for modern adults than older methods. Very low intakes are deliberately avoided here, because aggressive deficits risk muscle loss and nutrient gaps and should only be pursued under professional supervision.
Target = TDEE + goal adjustment (±250 or ±500 kcal/day)
The goal adjustment works because body fat stores a known amount of energy: roughly 7,700 kcal per kilogram. A sustained daily deficit of 500 kcal accumulates to about 3,500 kcal over a week, close to half a kilogram of fat, so subtracting 500 from maintenance targets that rate of loss. Adding calories reverses the arithmetic to support gradual weight gain.
Source:Mifflin-St Jeor equation, Am J Clin Nutr. 1990
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter sex, age, weight, height, activity level and goal.
- 2
Adjust the options
Adjust units if they apply — sensible defaults are already set.
- 3
Read your result
Target calories updates instantly as you type — no button to press.
Frequently asked questions
Is a 500-calorie deficit safe?
For most healthy adults a 500 kcal daily deficit is a sustainable pace that yields around half a kilogram of loss per week without excessive hunger or muscle loss. It becomes risky if it pushes intake very low, for example under 1,200 kcal for women or 1,500 for men. Smaller bodies may need a gentler deficit. If in doubt, aim for the slower rate and prioritise protein.
How many calories should I eat to lose weight?
Start from your maintenance calories, then subtract 250 to 500 per day for a loss of roughly a quarter to half a kilogram weekly. The exact number depends on your size, sex, age and activity, which is why this tool personalises it rather than quoting a flat figure. Avoid deficits so large that intake drops below the safe floors noted above.
Why has my weight loss stalled?
The most common reason is that maintenance calories fall as you lose weight, so a deficit that once worked becomes your new maintenance. Recalculate at your current weight and the target will drop. Water retention, inconsistent tracking and undercounting portions also mask real fat loss. Give any change three to four weeks before judging it, since weight fluctuates day to day.
Can I use this if I have a medical condition?
This is a general estimate, not medical advice, and conditions such as thyroid disorders, diabetes or pregnancy change calorie needs in ways the formula cannot see. If you have a diagnosed condition, take medication that affects appetite or metabolism, or are pregnant or breastfeeding, use the number only as a rough reference and set your actual targets with a doctor or registered dietitian.
How accurate is a calorie calculator?
The estimate is solid but not exact, typically within 10 to 15 percent of your true needs, because the activity multiplier and individual metabolism both introduce uncertainty. The reliable approach is to follow the target for two to three weeks, track your weight trend, and adjust by 100 to 200 calories if the scale is not moving as intended. Treat the output as a starting point, not a fixed rule.