Daily Calorie Needs Calculator UK
Work out your maintenance calories, pick a goal, and get a daily target with protein, carbohydrate and fat amounts. Everything updates instantly, in kg and cm, stone and pounds, or US pounds.
Protein and carbs at 4 kcal per gram; fat at 9 kcal per gram.
How to read your target
Your maintenance level (TDEE) is what keeps weight stable. A moderate deficit of roughly 10 to 20% below it is the sustainable zone for most people, in the same spirit as the NHS weight loss plan. Bigger is not better: aggressive deficits drive muscle loss, fatigue, hair shedding and rebound. Recalculate as your weight changes, keep protein and fluids first, and judge progress on your weekly trend, not single days.
On a GLP-1 medicine? Read this first
Medicines like Mounjaro create the deficit for you by suppressing appetite, so your job flips: use this page to check you are eating enough, not to push intake lower. Persistently landing far below your needs is a prescriber conversation, and anyone using insulin or a sulphonylurea should involve their diabetes team before deliberate intake changes. See calorie counting on treatment and the nutrition hub.
These are estimates, and floors matter more than ceilings
Calorie equations are accurate to within roughly 10% for most people, and real needs shift with sleep, hormones, illness and body composition. There is no universal safe minimum to chase: very low intakes need professional supervision, not an app. If you have a history of disordered eating, skip the numbers and speak to your GP; support matters more than any target.
Calorie questions
How many calories should I eat to lose weight?
Start from your maintenance level and take a moderate 10 to 20% deficit; the calculator above does this for you. There is no universal number: needs depend on size, age, sex and activity, and the target should be recalculated as your weight changes.
Is 1,200 calories a day safe?
For most adults it is too low to meet nutrient needs and risks muscle loss, fatigue and rebound. Very low calorie approaches exist but need professional supervision. A moderate deficit you can sustain beats an extreme one you cannot.
Do I need to hit my macros exactly?
No. Macro targets are guide rails, not pass or fail lines. Protein is the one most worth prioritising, especially during weight loss, because it protects muscle and keeps you full.
Why does my target change as I lose weight?
A smaller body burns fewer calories, so the same intake produces a shrinking deficit over time. Recalculating every 5 kg or so keeps the target honest, which is also why plateaus are normal rather than failure.
Where next
Read the guide →
Sources: NHS Better Health weight loss plan • British Dietetic Association food facts. Free tool by Monj (Medstack Ltd, Company No. 16439872) under our editorial and review policy. Educational estimates only; not medical advice; no personal data stored.