Calorie Calculator
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Results
About 1,914 calories a day to maintain your weight, from maintenance calories of 1,914 (Mifflin–St Jeor, lightly active, × 1.375).
| Goal | kcal/day | Change |
|---|---|---|
| Lose 2 lb a week | 914 (below 1,200) | −1,000 |
| Lose 1.5 lb a week | 1,164 (below 1,200) | −750 |
| Lose 1 lb a week | 1,414 | −500 |
| Lose 0.5 lb a week | 1,664 | −250 |
| Maintain weight (your goal) | 1,914 | – |
| Gain 0.5 lb a week | 2,164 | +250 |
| Gain 1 lb a week | 2,414 | +500 |
Maintenance calories are a starting point. Formulas can be off by 10% or more for an individual, so track your weight for two to three weeks and adjust by 100 to 200 calories a day if it drifts.
Calorie needs are different in pregnancy and while breastfeeding, and these formulas do not cover them. This is an estimate from a published formula, not medical advice. Talk to a doctor or registered dietitian about your own situation.
How to use the calorie calculator
- Choose US or metric units, then enter your sex, age, height and weight.
- Pick the activity level that matches a typical week, not your best one. If you know your own multiplier, choose "Custom".
- Choose a goal. The table under the result shows the daily calories for every goal, so you can compare a slower and a faster pace.
- Optionally switch the formula. Katch–McArdle uses your body fat percentage instead of age and sex.
Calorie formulas
Revised Harris–Benedict BMR = 88.362 + 13.397 × kg + 4.799 × cm − 5.677 × age (men)
= 447.593 + 9.247 × kg + 3.098 × cm − 4.330 × age (women)
Katch–McArdle BMR = 370 + 21.6 × lean body mass (kg)
Maintenance calories = BMR × activity multiplier
Target = maintenance ± (weekly change × 3,500 kcal per lb, or 7,700 kcal per kg) ÷ 7
Basal metabolic rate (BMR) is the energy your body uses at complete rest. Multiplying it by an activity factor, from 1.2 for a sedentary day to 1.9 for very hard training, estimates your total daily energy expenditure (TDEE), the calories that keep your weight stable. Weight is in kilograms, height in centimeters and age in years; the calculator converts pounds and inches for you. A 2005 systematic review by Frankenfield and colleagues found Mifflin–St Jeor the most reliable of the common equations, within 10% of measured resting energy in more people than the others, which is why it is the default.
Worked example
A 35-year-old woman who is 5 ft 6 in (167.6 cm) and weighs 150 lb (68 kg) has a Mifflin–St Jeor BMR of 10 × 68 + 6.25 × 167.6 − 5 × 35 − 161 = 1,392 kcal a day. She is lightly active, so her maintenance calories are 1,392 × 1.375 = 1,914 kcal. To lose about 1 lb a week she would aim for 1,914 − 500 = 1,414 kcal. Losing 2 lb a week would mean 914 kcal, which is below the 1,200 kcal minimum for women, so the calculator shows a warning. The revised Harris–Benedict equation gives her a BMR of 1,445 kcal, a little higher. That is common: in Mifflin's 1990 study the original Harris–Benedict equations overestimated measured resting energy by about 5%.
Maintenance calories by activity level
Estimated with Mifflin–St Jeor for two 35-year-olds: a woman 5 ft 4 in and 140 lb (63.5 kg), and a man 5 ft 10 in and 180 lb (81.6 kg).
| Activity level | Multiplier | Woman, kcal/day | Man, kcal/day |
|---|---|---|---|
| Sedentary | × 1.2 | 1,578 | 2,109 |
| Lightly active | × 1.375 | 1,808 | 2,417 |
| Moderately active | × 1.55 | 2,038 | 2,724 |
| Very active | × 1.725 | 2,268 | 3,032 |
| Extra active | × 1.9 | 2,499 | 3,340 |
Calories for losing or gaining weight
The calculator uses the long-standing rule that a pound of body weight is worth about 3,500 kcal (about 7,700 kcal per kilogram). It is an approximation: as you lose weight, your body needs less energy, so the same intake produces slower loss over the months, and early changes include water as well as fat. For a projection that models this, use the NIH Body Weight Planner, based on research by Kevin Hall and colleagues at the National Institutes of Health.
| Weekly change (US) | kcal a day | Weekly change (metric) | kcal a day |
|---|---|---|---|
| Lose 2 lb a week | −1,000 | Lose 1 kg a week | −1,100 |
| Lose 1.5 lb a week | −750 | Lose 0.75 kg a week | −825 |
| Lose 1 lb a week | −500 | Lose 0.5 kg a week | −550 |
| Lose 0.5 lb a week | −250 | Lose 0.25 kg a week | −275 |
| Gain 0.5 lb a week | +250 | Gain 0.25 kg a week | +275 |
| Gain 1 lb a week | +500 | Gain 0.5 kg a week | +550 |
Harvard Health advises that calorie intake should not fall below 1,200 a day for women or 1,500 a day for men except under the supervision of a health professional, because very low intakes make it hard to get enough nutrients. If a goal would take you below that, the calculator flags it: choose a slower pace or get medical advice first.
Tips for using your number
- Treat it as a starting point. Any formula can be off by 10% or more for one person. Weigh yourself at the same time of day for two to three weeks and adjust by 100 to 200 calories if your weight moves in the wrong direction.
- Be honest about activity. Overestimating activity is the most common reason the numbers don't match real life. For exercise-by-exercise figures, use the calories burned calculator.
- Quality matters too. Split your calories into protein, carbohydrate and fat with the macro calculator, or compare formulas side by side in the BMR calculator and TDEE calculator.
- Some situations need individual advice. Pregnancy, breastfeeding, diabetes, eating disorders and many medical conditions change what is right for you.
This is not medical advice; talk to a doctor or registered dietitian.
Sources
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51(2):241–247.
- Roza AM, Shizgal HM. The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass. Am J Clin Nutr 1984;40(1):168–182.
- McArdle WD, Katch FI, Katch VL. Exercise Physiology: Nutrition, Energy, and Human Performance (Katch–McArdle equation).
- Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc 2005;105(5):775–789.
- Hall KD et al. Quantification of the effect of energy imbalance on bodyweight. Lancet 2011;378:826–837, and the NIH Body Weight Planner.
- Harvard Health Publishing, Calorie counting made easy (updated April 2024).
Frequently asked questions
How many calories should I eat a day?
It depends on your size, age, sex and activity. With the Mifflin–St Jeor equation, a lightly active 35-year-old woman who is 5 ft 6 in and 150 lb burns about 1,914 calories a day, and a lightly active 35-year-old man who is 5 ft 10 in and 180 lb about 2,417. Eating close to that amount keeps weight roughly stable.
How many calories should I eat to lose a pound a week?
The usual rule of thumb is about 500 calories a day below your maintenance calories, because a pound is taken to be worth about 3,500 calories. For the woman above that is 1,914 − 500 = about 1,414 calories a day. The rule is an approximation: weight loss usually slows over time, which the NIH Body Weight Planner models.
What is the minimum number of calories I should eat?
Harvard Health advises that calorie intake should not fall below 1,200 a day for women or 1,500 a day for men except under the supervision of a health professional. If a goal would put you below that, choose a slower rate or talk to a doctor or registered dietitian first.
Which calorie formula is the most accurate?
For most adults, Mifflin–St Jeor. A 2005 systematic review found it estimated resting energy within 10% of measured values in more people than other common equations. The revised Harris–Benedict equation tends to come out a little higher (1,445 vs 1,392 kcal of BMR for the woman above), and Katch–McArdle is useful if you know your body fat percentage accurately.
Why does my weight not match the calculator?
Formulas estimate an average, and any one person can differ by 10% or more. Activity is easy to overestimate, food portions are easy to underestimate, and the body adapts as weight changes. Track your weight for two to three weeks, then adjust your intake by 100 to 200 calories a day.