Calorie Calculator – How Many Calories Do I Need?

How to Use the Calorie Calculator

Using this calorie calculator is simple: select your sex, enter your age in years, height in cm, and weight in kg, then choose your activity level (from sedentary to extra active). Click “Calculate my calories.” You will see your BMR (basal metabolic rate), your TDEE (total daily energy expenditure – that’s your maintenance calories), and recommended daily calories to maintain weight, to lose weight (with 15–20% and 25% deficit options), and to gain weight (with a small surplus). No need to choose a goal in advance – one result block shows all three so you can compare and decide.

How the Calorie Calculator Works

The calculator first estimates your BMR (basal metabolic rate) – the calories your body burns at rest – using the Mifflin-St Jeor equation. It then multiplies BMR by your activity level (from 1.2 for sedentary to 1.9 for extra active) to get your TDEE (total daily energy expenditure). That number is your maintenance calories: the calories to maintain your current weight. From there we derive calories to lose weight (by applying a deficit) and calories to gain weight (by adding a surplus). For more detail on BMR and TDEE, see our BMR calculator and TDEE calculator.

Calories to Maintain Weight

Your maintenance calories are the same as your TDEE: the number of calories you need per day to keep your weight stable at your current activity level. The calorie calculator shows this as “Maintain weight: X kcal/day.” A maintenance calorie calculator is exactly what we provide here – one result that answers “how many calories to maintain my weight.”

Calories to Lose Weight

To lose weight you need to eat below your maintenance calories (a calorie deficit). We show two ranges: a 15–20% deficit (safe and sustainable for most people) and a 25% deficit (faster but more aggressive; we show a short warning). So if you search for “calorie calculator to lose weight,” you get both a safe range and a faster option in one place. For a single target with a chosen deficit percentage, use our calorie deficit calculator.

Calories to Gain Weight

To gain weight (or build muscle) you need to eat above your maintenance calories – a calorie surplus. We show a small surplus (e.g. +300 kcal or +500 kcal per day) so you can gain gradually without excessive fat gain. A “calorie calculator to gain weight” or “calorie calculator to gain muscle” does exactly this: takes your TDEE and adds a modest surplus. If you need a custom surplus, add it to your TDEE yourself (e.g. TDEE + 300).

Who Is the Calorie Calculator For?

This calorie calculator is for anyone who wants to know how many calories do I need per day – whether to maintain weight, lose weight, or gain weight. It is useful if you are starting a diet, planning meals, or comparing your current intake to your needs. Because it shows all three goals (maintain, lose, gain) in one go, it suits people who are not yet sure of their goal or want to see options side by side. It works for both women and men; the formula uses sex, age, height, weight and activity level.

How Accurate Is the Calorie Calculator?

The calculator uses the Mifflin-St Jeor equation for BMR, which is widely used in research and clinical practice. Accuracy depends mainly on how honestly you choose your activity level – that part is an estimate. In general, BMR and TDEE estimates are within about 10–15% of reality for most adults. Recalculate when your weight or activity changes. This tool is for information and planning only; it does not replace advice from a doctor or dietitian.

Limitations and Disclaimer

This calorie calculator is for screening and information only. It is not intended for children or for pregnant or breastfeeding women. It does not replace professional medical or dietetic advice. Consult a doctor or dietitian for personalised nutrition and health advice.

Related Calculators

Use our TDEE calculator for maintenance calories only; our BMR calculator for resting metabolic rate; and our calorie deficit calculator to set a single daily target for weight loss (with 15%, 20%, or 25% deficit). For calories burned during exercise, try our calorie burn calculator; for calories in food, see our product calorie calculator and calorie table.

Frequently asked questions