How many calories should I eat to lose weight?

To lose weight, eat fewer calories than you burn each day. The reliable way to set a target is to estimate the calories you burn in a day (your total daily energy expenditure, or TDEE), then subtract a modest amount: about 500 calories a day produces roughly half a kilogram of fat loss a week. For most UK adults that lands somewhere between 1,500 and 2,200 calories a day, but it depends on your size, age and activity. This is general information, not personalised dietary advice.

Weight loss is not magic. If you take in less energy than your body uses, it makes up the difference from stored fat. The whole job is working out how much energy you use, then eating a sensible amount less than that.

Step 1: estimate your maintenance calories

Your maintenance level is your TDEE: the calories that keep your weight steady. It is your basal metabolic rate (what you burn at rest) multiplied by an activity factor. FitCalcs uses the Mifflin-St Jeor equation, the formula the British Dietetic Association and most clinicians rely on. The fastest way to get your number is the calorie and TDEE calculator, which shows every step.

Step 2: subtract a modest deficit

A kilogram of body fat holds roughly 7,700 calories. A daily deficit of about 500 calories therefore takes off around half a kilogram a week. That is the rate the NHS describes as safe and sustainable for most people. Going harder rarely pays off: very large deficits cost you muscle, energy and adherence, and the weight tends to come back.

• About 250 calories below maintenance: roughly 0.25 kg a week, gentle and easy to live with.
• About 500 calories below maintenance: roughly 0.5 kg a week, the usual sweet spot.
• Below about 1,500 calories a day for men or 1,200 for women, see a GP or dietitian first.

Step 3: review after two weeks

The equations give an estimate, not a promise. Weigh yourself a few times a week, take a two-week average, and if the scale is not moving as expected, adjust by about 100 calories. Water weight, salt and the menstrual cycle all move the number day to day, so trends over weeks matter more than any single morning.

Why context helps

Around 64% of UK adults are overweight or living with obesity, per the NHS Health Survey for England, so if you are setting a deficit you are in good company. You can see the full picture, and how you compare, on the UK fitness statistics page. To check your current standing, the BMI and waist-to-height calculator is a useful starting point.

Informational only, not medical or dietary advice. If you have a health condition, are pregnant, or take medication, speak to a GP or registered dietitian before changing your diet.