The short answer
Most adult women need somewhere between 1,600 and 2,400 calories a day to keep their weight steady, and most adult men between 2,000 and 3,000. Where you fall depends on your size, age, sex and, above all, how much you move. To lose about half a kilogram (one pound) a week, eat around 500 calories less than that.
The quickest way to get a personal figure is the calorie intake calculator. The rest of this guide explains what sits behind the number, so you can use it well.
Step 1: estimate what you burn
Your body spends energy in a few ways. Most of it, around two thirds, goes on simply staying alive: your heart, lungs, brain and organs. This is your basal metabolic rate. On top of that comes every movement you make during the day, any exercise, and the small cost of digesting food. Add them together and you get your total daily energy expenditure, or TDEE.
Calculators estimate BMR from your height, weight, age and sex, then multiply it by an activity factor. The TDEE calculator shows the result for every activity level side by side.
Step 2: set the gap for your goal
- To lose weight: subtract 250 to 750 kcal a day. 500 is a good default.
- To maintain: eat at your TDEE.
- To gain weight or build muscle: add 250 to 500 kcal a day, and lift weights.
Bigger gaps work faster on paper, but people rarely keep them up. A pace you can hold for three months beats a pace you can hold for three weeks.
Step 3: test it for two to three weeks
A formula can only get you within a few hundred calories. The real test is your weight trend. Weigh yourself first thing in the morning, three or more times a week, and compare weekly averages.
| After 2–3 weeks your average weight is… | What to do |
|---|---|
| Falling at about your target pace | Keep going. Recalculate after every 4–5 kg. |
| Falling much faster | Eat 100–200 kcal more. Fast loss is harder to sustain. |
| Not moving | Check your tracking first, then eat 100–200 kcal less or walk more. |
| Going up | Your real TDEE is lower than estimated. Reduce by 200–300 kcal. |
Calories are not the whole story
Total calories decide whether your weight goes up or down. What those calories are made of decides how full you feel, how much muscle you keep and how healthy you are. A few habits make any target easier:
- Protein at every meal. See the protein calculator for a target.
- Plenty of vegetables, fruit, legumes and whole grains for fibre.
- Fewer drinks with calories, and fewer ultra-processed snacks that are easy to overeat.
- Enough sleep. Short sleep raises appetite the next day.
When not to use a calorie target
Calorie counting is not right for everyone. If you are pregnant or breastfeeding, under 18, managing diabetes or another medical condition, or if tracking food makes you anxious or has been part of disordered eating in the past, please talk to a doctor or registered dietitian before setting a target. In the UK, Beat (beateatingdisorders.org.uk) and in the US, the National Alliance for Eating Disorders (allianceforeatingdisorders.com) offer free support.
Frequently asked questions
Is 2,000 calories a day a lot?
Should I eat the same calories every day?
This guide is general information, not medical advice. See our disclaimer and how we calculate.