Calorie Calculator
How many calories a day to lose, keep or gain weight at a pace you can keep up, with a week-by-week path to your goal weight. It never suggests less than the guideline floors.
How active you are
Lightly active · 5,000–7,500 steps a day. A desk job with some walking, or 1–3 workouts a week. × 1.55
More optionsMifflin-St Jeor
From a body-composition scan or scale. It lets you use Katch-McArdle, which works from lean mass.
BMR equation
Why sex? The equations were fitted on people recorded as male or female, so they need one. If neither fits your body, try both: you are likely between the two.
ExampleA 35-year-old woman, 72 kg, 165 cm
1,800kcal a day
400 below your maintenance of about 2,190.
65 kg in about 19 weeks. Maintenance moves with your weight: about 2,090 kcal at 65 kg, so re-check every few weeks.
The page never goes under 1,200 kcal for women or 1,500 for men, or faster than 1% of your weight (at most 1 kg) a week.
- Maintenance (likely range)
- 2,020–2,370 kcal
- Protein
- 115 g a day
General information from published research, not a diagnosis or medical advice. Talk to a doctor before changing medication or treatment. An estimate for adults, not for pregnancy or breastfeeding; if eating feels hard or stressful, talk to a doctor. Terms
Your maintenance caloriesAbout 2,190 kcal a day
- At rest (BMR)1,420
- Moving and exercise560
- Digesting food220
About 2,190 kcal a day, likely 2,020–2,370: your BMR of 1,420 × 1.55 for lightly active.
Your macros115 g protein · 200 g carbs · 60 g fat
Protein at 1.6 g/kg, where extra stopped adding muscle in trials; fat at 30% of calories; carbs the rest.
- Protein115 g26% of calories30 g a meal
- Carbs200 g44% of calories50 g a meal
- Fat60 g30% of calories15 g a meal
For 1,800 kcal a day. Aim for about 25 g of fibre too (14 g per 1,000 kcal).
Adjust from your real resultsAfter 2–3 weeks, let your scale correct the estimate
Every equation is an estimate. After a few weeks of eating about the same each day, your weight trend shows your real maintenance: each kilogram lost is about 7,700 kcal your body took from its stores. Use the average of several weigh-ins at each end, since water moves the scale day to day.
Over the last
How this works: Method, 11 sources, Checked against 5 worked examples,
How this works
Method
Start from your maintenance: your BMR from the Mifflin-St Jeor equation times the multiplier for your activity level. To lose weight, the page takes away the calories that match your chosen pace, at 7,700 kcal for each kilogram (the long-standing 3,500 kcal a pound). To gain, it adds them. Full method
Sources
- 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults (Circulation, 2014)
- NHS, Obesity: treatment
- Hall et al., Quantification of the effect of energy imbalance on bodyweight (Lancet, 2011)
- Hall, What is the required energy deficit per unit weight loss? (Int J Obes, 2008)
- A new predictive equation for resting energy expenditure in healthy individuals (Mifflin et al.) (Am J Clin Nutr, 1990)
- The Harris Benedict equation reevaluated (Roza and Shizgal) (Am J Clin Nutr, 1984)
- Comparison of predictive equations for resting metabolic rate: a systematic review (Frankenfield et al.) (J Am Diet Assoc, 2005)
- Human energy requirements: report of a joint FAO/WHO/UNU expert consultation (FAO, 2004)
- A meta-analysis of protein supplementation and resistance training (Morton et al.) (Br J Sports Med, 2018)
- ISSN position stand: protein and exercise (Jäger et al.) (J Int Soc Sports Nutr, 2017)
- Dietary Guidelines for Americans, 2020–2025, Appendix 1 (USDA and HHS, 2020)
How it’s tested
5 worked examples for this page are checked by automated tests before every release: given the inputs, the tool must show the expected answer.
Limits
General information from published research, not a diagnosis or medical advice. Talk to a doctor before changing medication or treatment. An estimate for adults, not for pregnancy or breastfeeding; if eating feels hard or stressful, talk to a doctor.
Changes
- First published: maintenance calories as a range, calories for your goal with a week-by-week timeline, macros and protein, with calorie, macro, BMR and protein calculator pages.
How the calories for your goal are worked out
Start from your maintenance: your BMR from the Mifflin-St Jeor equation times the multiplier for your activity level. To lose weight, the page takes away the calories that match your chosen pace, at 7,700 kcal for each kilogram (the long-standing 3,500 kcal a pound). To gain, it adds them.
Worked example: a man of 42, 180 cm and 88 kg who is active (7,500–10,000 steps a day). BMR = 10 × 88 + 6.25 × 180 − 5 × 42 + 5 = 1,800 kcal; × 1.70 = 3,060 kcal of maintenance. A steady 0.5% of 88 kg is 0.44 kg a week, × 7,700 ÷ 7 = 484 kcal a day, so his target is about 2,580 kcal. At that pace, 80 kg is about 18 weeks away.
The pace is a share of your weight, not a fixed number, because a kilogram means more to a small person than a large one. Losing 0.5 to 1% of body weight a week is the range sports dietitians use to keep muscle, and the NHS advises 0.5 to 1 kg a week. The page caps every pace at 1 kg a week and never goes under the guideline floor, whatever you pick.
Target = maintenance − (kg a week × 7,700 ÷ 7), never under 1,200 kcal (women) or 1,500 kcal (men)
- Diets for weight loss usually prescribe 1,200–1,500 kcal a day for women and 1,500–1,800 for men, or a deficit of 500 or 750 kcal a day. Source: 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults (Circulation, 2014).
- “Aim to lose 1 to 2lbs, or 0.5 to 1kg, a week.” Source: NHS, Obesity: treatment.
- Weight changes slowly after a change in intake, with half times of about a year, because expenditure falls as weight falls; the 3,500 kcal rule alone over-predicts loss. Source: Hall et al., Quantification of the effect of energy imbalance on bodyweight (Lancet, 2011).
- The 3,500 kcal per pound rule roughly matches people with more than 30 kg of body fat and overestimates the deficit needed by leaner people. Source: Hall, What is the required energy deficit per unit weight loss? (Int J Obes, 2008).
Calories a day by activity and goal
For a woman of 35, 165 cm and 72 kg (the calculator’s example), rounded to 10 kcal. Losing gently is 0.25% of body weight a week, steadily 0.5%, at the upper limit 1%; gaining gently is 0.25%.
| Activity | Maintain | Lose gently | Lose steadily | Upper limit | Gain gently |
|---|---|---|---|---|---|
| Mostly sitting | 1,980 | 1,780 | 1,590 | 1,200 | 2,180 |
| Lightly active | 2,190 | 2,000 | 1,800 | 1,400 | 2,390 |
| Active | 2,410 | 2,210 | 2,010 | 1,610 | 2,600 |
| Very active | 2,620 | 2,420 | 2,220 | 1,830 | 2,820 |
| Athlete or heavy labour | 3,110 | 2,920 | 2,720 | 2,320 | 3,310 |
Frequently Asked Questions
How many calories a day should I eat to lose weight?
Enough under your maintenance to lose 0.5 to 1% of your weight a week: for someone of 80 kg, 0.5% is 0.4 kg a week, or 440 kcal a day under maintenance. The calculator works it out from your own maintenance and pace, and holds the target at 1,200 kcal for women or 1,500 for men if the pace would take you lower.
Why does my calorie target change as I lose weight?
A smaller body uses less energy, at rest and when it moves. If you keep eating the first target, your deficit shrinks and the loss slows, which is the plateau most people meet. The timeline assumes you re-check every few weeks, and the page shows your maintenance at the goal weight so you know where you will land.
Is 1,200 calories a day safe?
It is the lowest intake the 2013 US obesity guideline prescribes for women; for men the low end is 1,500. The NHS calls diets under 800 or 1,200 calories very low calorie diets, says they are not suitable or safe for everyone, and offers them with a dietitian’s support. This page never suggests less than those floors.
How fast can I lose weight safely?
The NHS advises 0.5 to 1 kg (1 to 2 lb) a week. A share of body weight scales better: 0.5 to 1% a week is what sports dietitians use to keep muscle while losing fat. The faster paces here are capped at 1 kg a week.
How many calories to gain weight or build muscle?
A small surplus: about 0.25 to 0.5% of body weight a week, which a 2019 review of off-season bodybuilders put at 10–20% above maintenance. More than that adds fat faster than muscle. Pair it with strength training and enough protein.