Calorie Calculator
Estimate how many calories you burn each day (TDEE) from your age, sex, weight, height and activity level, using the Mifflin-St Jeor equation — instantly, right in your browser.
How to Use the Calorie Calculator
- Choose your units: Pick Metric (kg, cm) or Imperial (lb, feet and inches) with the toggle.
- Enter your details: Type your age, choose male or female, and enter your weight and height. Results appear as soon as every field is filled in.
- Pick an activity level: Choose the option that matches a typical week, not your best week. The table further down describes each level.
- Read the results: Your daily calories (TDEE), your BMR, and the −500 and +500 calorie targets update instantly. Use Share to copy the numbers with a link to this page.
What You'll Discover
- Daily Calories (TDEE) — your estimated Total Daily Energy Expenditure, the calories you burn in a typical day at the activity level you chose. Eating around this number is the usual starting point for keeping your weight steady.
- BMR — your estimated resting energy use, from the Mifflin-St Jeor equation. It is the starting point for TDEE before the activity multiplier is applied.
- Lose weight (−500) — your TDEE minus 500 calories, an example target for a moderate daily deficit. If that figure would fall below 1,000 calories, the calculator shows “Not advised” instead of a number.
- Gain weight (+500) — your TDEE plus 500 calories, an example target for a daily surplus.
“Calories” here means the food calories (kilocalories) you see on nutrition labels. Every result is an estimate for planning, not a measurement of your body, and it is not medical advice. If you have a health condition, take medication, or are thinking about a large change to what you eat, talk to a doctor or registered dietitian first.
How the Calorie Calculator Works
The calculator works in two steps. First it estimates your BMR with the Mifflin-St Jeor equation, then it multiplies that by an activity factor to get your TDEE. Weight is in kilograms, height in centimetres and age in years (the imperial fields are converted first, using 1 lb = 0.453592 kg and 1 in = 2.54 cm).
Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161
TDEE = BMR × activity multiplier
The equation comes from a 1990 study in the American Journal of Clinical Nutrition that measured resting energy expenditure in 498 healthy people. According to the abstract, the fitted equation explained 71% of the variation in resting energy expenditure, fat-free mass was the strongest single predictor, and the older Harris-Benedict equations overestimated measured expenditure by about 5% (Mifflin et al., 1990, PubMed). In plain terms, weight, height, age and sex capture a lot of the picture but not all of it, so two people with identical numbers can still burn different amounts.
What each input does to your BMR
| Change | Effect on BMR | Effect on TDEE at × 1.55 |
|---|---|---|
| +1 kg of body weight | +10 cal | +15.5 cal |
| +1 cm of height | +6.25 cal | about +9.7 cal |
| +1 year of age | −5 cal | about −7.75 cal |
| Male instead of female | +166 cal (5 − (−161)) | about +257 cal |
Worked example
A 30-year-old man who weighs 80 kg, is 180 cm tall and is moderately active: BMR = 800 + 1,125 − 150 + 5 = 1,780 calories. TDEE = 1,780 × 1.55 = 2,759 calories. The −500 target is 2,259 and the +500 target is 3,259.
Activity Levels and Multipliers
The activity multiplier is a rule-of-thumb factor applied on top of BMR. It is a common convention rather than part of the Mifflin-St Jeor equation itself, and it is the least precise part of the estimate because “moderately active” means different things to different people. The table shows the five levels the calculator uses, with the TDEE each would give the worked example above (BMR 1,780).
| Activity level | What it usually looks like | Multiplier | TDEE for BMR 1,780 |
|---|---|---|---|
| Sedentary | Desk job, little or no exercise | 1.2 | 2,136 |
| Lightly active | Exercise 1-3 days a week, or a job with some walking | 1.375 | 2,448 |
| Moderately active | Exercise 3-5 days a week | 1.55 | 2,759 |
| Very active | Hard exercise 6-7 days a week | 1.725 | 3,071 |
| Extra active | Intense daily training or a very physical job | 1.9 | 3,382 |
Moving one step up the scale adds a lot: going from sedentary to moderately active raises this example from 2,136 to 2,759, a difference of 623 calories a day. That is why an honest choice matters more than any other input.
How to choose
- Base the choice on an average week, including rest days, rather than on your most active days.
- If you sit between two levels, pick the lower one, then adjust after a few weeks of real-world results.
- The multiplier is meant to cover everything you do above resting, including exercise sessions. Do not add workout calories on top of the result, or you will count them twice.
Setting a Calorie Target and Knowing the Limits
Your TDEE is a maintenance estimate. Eating below it is a deficit and eating above it is a surplus. The table shows how that looks for the worked example (TDEE 2,759). The calculator displays the −500 and +500 rows; the ±250 rows are simple arithmetic you can do yourself.
| Goal | Daily change | Daily calories |
|---|---|---|
| Lose weight, larger deficit | −500 | 2,259 |
| Lose weight, smaller deficit | −250 | 2,509 |
| Maintain | 0 | 2,759 |
| Gain weight, smaller surplus | +250 | 3,009 |
| Gain weight, larger surplus | +500 | 3,259 |
Pace of weight loss
The CDC says that people who lose weight at a gradual, steady pace of about 1 to 2 pounds a week are more likely to keep the weight off than people who lose it more quickly (CDC: Losing Weight). Be careful with the popular rule that a 3,500-calorie deficit equals one pound. A 2013 commentary that tested it against seven supervised experiments concluded that the rule grossly overestimates actual weight loss (Thomas et al., 2013, PubMed). Treat −500 as a starting point and watch your weight trend over several weeks instead of predicting an exact date.
Limits of any calorie calculator
- The NIH Body Weight Planner states that it is for adults aged 18 or older and not for younger people or for pregnant or breastfeeding women. It also notes that people often underestimate how much they eat and sets a minimum calorie goal of 1,000 calories a day (NIDDK Body Weight Planner). This calculator follows the same two cautions: it is built for adults, and it will not show a weight-loss target below 1,000 calories.
- It does not know your muscle mass, medical conditions or medications. For a body-composition estimate, try the body fat calculator.
How Many Calories Do I Need If...
These examples use the same formulas as the calculator, rounded to the nearest calorie. They are illustrations of the arithmetic, not recommendations for any one person.
How many calories do I need if I am a 30-year-old man, 80 kg and 180 cm, and train 3-5 days a week?
You need about 2,759 calories a day to maintain your weight. BMR is 1,780 calories, and 1,780 × 1.55 = 2,759. The −500 target is 2,259 and the +500 target is 3,259.
How many calories do I need if I am a 35-year-old woman, 65 kg and 165 cm, and lightly active?
You need about 1,850 calories a day to maintain your weight. BMR is 650 + 1,031.25 − 175 − 161 = 1,345 calories, and 1,345.25 × 1.375 = 1,850. The −500 target is 1,350 and the +500 target is 2,350.
How many calories do I need if I am a 28-year-old woman, 150 lb and 5 ft 5 in, with a desk job?
You need about 1,694 calories a day to maintain your weight. In metric, 150 lb is 68.04 kg and 5 ft 5 in is 165.1 cm, which gives a BMR of 1,411 calories. Multiplied by 1.2 for a sedentary day, that is 1,694. The −500 target is 1,194.
How many calories do I need if I am a 45-year-old man, 220 lb and 6 ft tall, with a desk job?
You need about 2,305 calories a day to maintain your weight. 220 lb is 99.79 kg and 6 ft is 182.88 cm, so BMR is 1,921 calories and 1,921 × 1.2 = 2,305. The −500 target is 1,805.
How many calories do I need if I am a 25-year-old woman, 60 kg and 170 cm, and exercise 6-7 days a week?
You need about 2,374 calories a day to maintain your weight. BMR is 1,377 calories (1,376.5), and 1,376.5 × 1.725 = 2,374. Because the multiplier is large, a small misjudgement of your real activity moves this number a lot.
How many calories do I need if I am a 22-year-old man, 70 kg and 175 cm, and train intensely every day?
You need about 3,209 calories a day to maintain your weight. BMR is 1,689 calories and 1,688.75 × 1.9 = 3,209. Extra active is the top level, so choose it only if your daily training or work really is intense.
How many calories do I need if I am a 60-year-old man, 85 kg and 175 cm, and mostly sedentary?
You need about 1,979 calories a day to maintain your weight. BMR is 1,649 calories (1,648.75), and 1,648.75 × 1.2 = 1,978.5, which the calculator rounds to 1,979. The −500 target is 1,479.
How many calories do I need if I get 10 years older?
You need about 77 fewer calories a day, if everything else stays the same. The equation subtracts 5 calories of BMR for each year, so 10 years is 50 calories, and at × 1.55 that is 77.5 calories of TDEE. The 30-year-old man above would go from 2,759 to 2,682 at age 40.
How many calories do I need if I move from a desk job to exercising 3-5 days a week?
You need more calories, because the multiplier rises from 1.2 to 1.55. For a BMR of 1,780, TDEE goes from 2,136 to 2,759, an extra 623 calories a day. Eating the old amount while doing the new activity creates a deficit without any other change.
How many calories do I need if I am a small, older woman who wants to lose weight?
The calculator will not show a weight-loss target if it falls below 1,000 calories. Take a 60-year-old woman who is 50 kg, 150 cm and sedentary: BMR is 977 calories and TDEE is 1,172, so a −500 target would be 672 calories. The result shows “Not advised”. For someone with a TDEE this low, a smaller change or a plan from a doctor or dietitian is the better route.
People Also Search For
How to calculate TDEE by hand
Work out BMR with the Mifflin-St Jeor equation, then multiply by your activity factor. For a 30-year-old man of 80 kg and 180 cm: 10 × 80 = 800, 6.25 × 180 = 1,125, and 5 × 30 = 150, so BMR = 800 + 1,125 − 150 + 5 = 1,780. With a factor of 1.55, TDEE = 1,780 × 1.55 = 2,759 calories.
What is the difference between BMR and TDEE?
BMR is the estimated energy your body uses at rest; TDEE is that figure scaled up for your activity. The two are linked by the multiplier, so TDEE is always at least 1.2 times BMR in this calculator. In the worked example, BMR is 1,780 and TDEE is 2,136 for a sedentary day or 3,382 for extra active.
Mifflin-St Jeor vs Harris-Benedict
Mifflin-St Jeor was designed as a newer predictive equation, and in its 1990 study the older Harris-Benedict equations overestimated measured resting expenditure by about 5%. That is the only comparison this page makes, because it comes from the paper’s abstract. Neither equation measures your own metabolism, so both are estimates (PubMed abstract).
How many calories to lose 1 pound a week
The popular rule says a 500-calorie daily deficit adds up to 3,500 calories, or one pound, a week, but it is a rough guide at best. Research that compared the rule with supervised weight-loss experiments found it grossly overestimates the loss, so real progress is usually slower than the arithmetic suggests. Use it to pick a starting target, then adjust to your own weight trend.
Calorie calculator in pounds and inches
Switch the toggle to Imperial and enter pounds, feet and inches; the calculator converts them for you. It multiplies pounds by 0.453592 to get kilograms and turns feet and inches into total inches, multiplied by 2.54 for centimetres. For 150 lb and 5 ft 5 in that is 68.04 kg and 165.1 cm. You can use feet only, inches only, or both.
What is zigzag calorie cycling?
Zigzag cycling means eating different amounts on different days while keeping the weekly total on target. For the worked example with a −500 target of 2,259 a day, the weekly total is 15,813 calories. You could eat 2,443 on five days and 1,800 on two days (15,815 in total) and land within a few calories of the same week. Whether it suits you is a matter of preference; the arithmetic is the same.
Frequently Asked Questions
What is TDEE?
TDEE stands for Total Daily Energy Expenditure, the estimated number of calories you burn in a typical day. In this calculator it is your BMR multiplied by an activity factor between 1.2 and 1.9. Eating about that many calories is the usual starting point for maintaining your weight, while eating less is a deficit and eating more is a surplus.
Which equation does this calorie calculator use?
It uses the Mifflin-St Jeor equation for BMR: (10 × kg) + (6.25 × cm) − (5 × age) + 5 for men, and the same with − 161 instead of + 5 for women. It then multiplies by 1.2, 1.375, 1.55, 1.725 or 1.9 depending on the activity level you pick. It does not use body-fat percentage, so it is not the Katch-McArdle method.
How accurate is this calculator?
It gives an estimate, not a measurement. The 1990 study behind the equation reported that it explained 71% of the variation in measured resting energy expenditure among 498 healthy people, so a good share of individual difference is not captured. The activity multiplier adds more uncertainty. Use the result as a starting point and compare it with how your weight changes over a few weeks.
How many calories should I eat to lose weight?
A common starting point is your TDEE minus 500 calories, which is the figure the calculator shows. The CDC notes that a gradual pace of about 1 to 2 pounds a week is linked with a better chance of keeping the weight off than faster loss. The calculator will not show a target under 1,000 calories. For a personal plan, speak to a doctor or registered dietitian.
Why does the weight-loss row say “Not advised”?
It appears when your TDEE minus 500 would be under 1,000 calories a day, which happens when your TDEE is below 1,500. That can occur for a small, older or very sedentary person. Rather than show a very low number, the calculator leaves it out. NIDDK’s Body Weight Planner likewise requires calorie goals of at least 1,000 a day.
How many calories should I eat to gain weight or build muscle?
The calculator shows TDEE plus 500 as an example surplus, and a smaller surplus such as +250 is simple arithmetic you can do yourself. These are starting points, not predictions of how fast you will gain, and calories alone do not decide whether the gain is muscle or fat. A coach, doctor or dietitian can help you set a plan.
Why do men and women get different results?
The equation has a different constant for each: +5 for men and −161 for women, a gap of 166 calories of BMR. For a 70 kg, 170 cm, 30-year-old at a moderate activity level, that gives a TDEE of 2,507 for the male version and 2,250 for the female version. The calculator offers only these two options.
Does the calculator account for my muscle mass or body fat?
No. It uses weight, height, age and sex only. The original study reported that fat-free mass was the strongest single predictor of resting energy expenditure, so a very muscular or very lean person may burn more than the estimate, and the opposite may hold for someone with less muscle. The body fat calculator can give you a rough body-composition figure.
Is it suitable for children, teenagers or pregnant women?
No. It is built for adults. NIDDK’s Body Weight Planner says its information is for adults aged 18 and over, and not for younger people or for pregnant or breastfeeding women. If you are under 18, pregnant, breastfeeding or managing a medical condition, ask a doctor or registered dietitian about your calorie needs.
Should I add the calories I burn exercising?
No. The activity multiplier is meant to cover your usual exercise, so adding workout calories on top counts them twice. If your week changes a lot, such as starting a training plan, choose a different activity level instead. The calculator does not estimate calories burned in a single workout.
Should I eat the same number of calories every day?
You can, or you can vary your intake across the week. What matters for the weekly total is the average. Eating 2,443 calories on five days and 1,800 on two gives 15,815 for the week, close to seven days at 2,259 (15,813). Choose whichever pattern you find easier to follow.
Why am I not losing weight at my calculated target?
Several things can explain it. The estimate may be off for your body, your activity level may be set too high, or your real intake may be higher than you think, since NIDDK notes that people often underestimate how much they eat. Weigh and log your food for a week, choose the lower activity level if unsure, and compare your average weight across weeks rather than day to day. See a doctor if you are concerned.
Is my data stored or sent anywhere?
No. All calculations run in your browser. Nothing you type is sent to a server or saved, and no account is needed.
Sources
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-7. PubMed.
- Thomas DM, Martin CK, Lettieri S, et al. Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? Commentary on a commonly accepted rule. Int J Obes. 2013;37(12):1611-3. PubMed.
- Centers for Disease Control and Prevention. Losing Weight.
- National Institute of Diabetes and Digestive and Kidney Diseases. Body Weight Planner.
This page is general information and not medical advice. Talk to a doctor or registered dietitian before changing your diet, especially if you have a health condition.
Last reviewed: November 2026 — formulas and worked examples verified.