How many calories should I eat a day?
- 1Choose your sex and enter your age, weight and height (cm or feet and inches, kg or lb).
- 2Pick the activity level that matches a normal week — count your job as well as exercise.
- 3Choose your goal: lose 0.25–1 kg a week, stay the same, or gain. Add a goal weight to see how long it takes.
- 4Read your daily calories, the step-by-step working and the table of calories for every goal.
How are daily calories calculated?
- 01BMR (Mifflin–St Jeor) = 10 × weight kg + 6.25 × height cm − 5 × age + 5 (men) or − 161 (women)
- 02BMR (Katch–McArdle, if body fat % known) = 370 + 21.6 × lean mass kg
- 03TDEE = BMR × activity factor (1.2, 1.375, 1.55, 1.725 or 1.9)
- 04Target = TDEE − (kg per week × 7,700 ÷ 7), never below 1,200 kcal (women) or 1,500 kcal (men)
- 05Weeks to goal = (current weight − goal weight) ÷ weekly change
Your body burns energy all day just to keep you alive — breathing, heartbeat, keeping warm. That is your basal metabolic rate (BMR). The Mifflin–St Jeor equation from 1990 is the formula the American Academy of Nutrition and Dietetics found the most accurate for most adults. If you know your body-fat percentage, the Katch–McArdle formula uses your lean mass instead, which is better for very muscular people.
Moving, working and exercising add to this. Multiplying BMR by an activity factor gives your total daily energy expenditure (TDEE): the calories that keep your weight the same. A desk job with little exercise is 1.2; hard daily training plus a physical job is 1.9.
A kilogram of body fat holds roughly 7,700 kcal, so losing 0.5 kg a week needs about 550 kcal a day less than your TDEE. Health services such as the NHS advise losing 0.5–1 kg a week. Eating too little makes it hard to get enough nutrients, so the calculator never goes below 1,200 kcal a day for women or 1,500 kcal for men — the limits Harvard Health gives for dieting without a doctor's supervision.
The goal date is a straight-line estimate. In real life weight loss slows slowly as your body gets lighter and needs fewer calories, so recalculate every 4–5 kg.
Example: calories for a 70 kg man
A 30-year-old man who weighs 70 kg and is 175 cm tall burns about 1,649 kcal a day at rest (the published Mifflin–St Jeor example gives 1,648.75).
Exercising 3–5 days a week, he keeps his weight on about 2,556 kcal a day.
To lose 0.5 kg a week he should eat about 2,006 kcal a day (a change of -550 kcal a day from maintenance).
Good to know
- Weigh yourself at the same time each morning and look at the weekly average — daily weight jumps up and down with water and salt.
- Fill up on protein (eggs, daal, chicken, yogurt) and vegetables: they keep you full on fewer calories.
- Oil and ghee add up fast: one tablespoon is about 120 kcal. Measuring it is the easiest saving in desi cooking.
- Recalculate after every 4–5 kg lost — a lighter body needs fewer calories.
Calorie calculator — common questions
How many calories should I eat a day to lose weight?
About 500–550 kcal less than your maintenance calories (TDEE) loses roughly 0.5 kg a week. For a moderately active 70 kg, 175 cm man of 30 that is about 2,000 kcal a day. The calculator works it out for you.
1 din mein kitni calories chahiye? (How many calories do I need in a day?)
Most adult women need about 1,800–2,400 kcal and most men 2,200–3,000 kcal a day, depending on age, size and activity. Enter your own details above for your number.
What is the lowest number of calories I can safely eat?
Without a doctor's supervision, not below 1,200 kcal a day for women or 1,500 kcal for men. Below that it is hard to get enough protein, vitamins and minerals.
What is TDEE?
Total daily energy expenditure — all the calories you burn in a day: your resting rate (BMR) plus digestion, daily movement and exercise. Eating your TDEE keeps your weight steady.
How fast can I lose weight safely?
0.5–1 kg (1–2 lb) a week. Faster loss usually means losing muscle and water, and the weight tends to come back.
Why am I not losing weight on my calories?
Calorie formulas can be 10–15 % off, and food is easy to underestimate — especially oil, sugar in tea and drinks. Track your food for a week, check portions, and lower your target by 100–200 kcal if your weekly average weight hasn't moved for 2–3 weeks.
Sources
- Mifflin MD, St Jeor ST et al. – A new predictive equation for resting energy expenditure in healthy individuals (Am J Clin Nutr, 1990)
- Frankenfield D et al. – Comparison of predictive equations for resting metabolic rate (J Am Diet Assoc, 2005)
- FAO/WHO/UNU – Human energy requirements (2004): physical activity levels
- Harvard Health Publishing – Calorie counting made easy (minimum 1,200 kcal women, 1,500 kcal men)
- NHS – Tips to help you lose weight: aim to lose 0.5 to 1 kg a week
- Hall KD – What is the required energy deficit per unit weight loss? (Int J Obes, 2008)
Formulas last reviewed: September 30, 2026 ·How we check our formulas