Calorie Calculator

Estimate how many calories you burn at rest and in a day, using the Mifflin-St Jeor equation and your activity level.

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Enter your values and select Calculate to see your result.

For general information onlyThis result is an estimate and does not replace advice from a healthcare professional.

This calculator estimates how many calories you burn at rest and in a typical day, then adjusts for your goal. It’s built on a published equation and published activity levels, and it’s a starting point, not a prescription.

How it’s calculated

First, the Mifflin-St Jeor equation estimates your calories at rest from your weight in kilograms, height in centimeters and age in years:

Males: 10 × weight + 6.25 × height − 5 × age + 5Females: 10 × weight + 6.25 × height − 5 × age − 161

Then your physical activity level turns that into the calories you need to maintain your weight. Your goal adjusts the result:

Maintenance = calories at rest × activity levelTarget = maintenance + goal

Worked example

A 30-year-old male who is 180 cm tall, weighs 80 kg and is moderately active, and who wants to lose weight:

  1. Calories at rest: (10 × 80) + (6.25 × 180) − (5 × 30) + 5 = 800 + 1,125 − 150 + 5 = 1,780.
  2. Maintenance: 1,780 × 1.6 = 2,848, which rounds to 2,850.
  3. Target: 2,850 − 500 = 2,350.

About 2,350 kcal a day, from a maintenance level of about 2,850.

Activity levels

Activity levelWhat it meansMultiplier
SedentaryDaily living only1.4
Moderately activeAlso walks 1.5–3 miles a day1.6
ActiveAlso walks more than 3 miles a day1.75
Very activeHard physical work or training2.0

FAO/WHO/UNU sets the range at 1.40–1.69 for sedentary or light lifestyles, 1.70–1.99 for active, and 2.00–2.40 for vigorous. The NIH uses 1.4 for sedentary, with a default of 1.6. Descriptions of the first three levels follow the US Dietary Guidelines.

How this compares with the US Dietary Guidelines

As a check, here is this calculator next to the published estimates for the guidelines’ reference adults, at age 30. The reference woman is 5 ft 4 in and 126 lb, and the reference man is 5 ft 10 in and 154 lb.

Reference adult, age 30This calculatorDietary Guidelines
Woman, sedentary1,7901,800
Woman, moderately active2,0402,000
Woman, active2,2302,400
Man, sedentary2,3302,400
Man, moderately active2,6602,600
Man, active2,9103,000

Common questions

What's the difference between BMR and maintenance calories?

BMR, or basal metabolic rate, is roughly what your body burns at rest over a day. Maintenance calories, sometimes called TDEE, add your daily activity on top. That's the amount that would keep your weight stable. The Mifflin-St Jeor equation technically estimates resting energy expenditure, which is close to BMR.

Why is my number higher than on other calculators?

Often because of the activity level. Some calculators multiply a sedentary BMR by 1.2. We use 1.4, the sedentary level in the NIH's Body Weight Planner and the low end of the FAO/WHO/UNU range for sedentary lifestyles. For the reference people in the US Dietary Guidelines, it gives results close to their published calorie estimates. Your own results over a few weeks are a better guide than any calculator.

How fast should I lose weight?

The CDC says that people who lose about 1 to 2 pounds a week are more likely to keep the weight off than people who lose it quicker. The NIH suggests that losing 5% to 10% of your weight over about 6 months is a reasonable aim. This calculator's weight loss option takes off 500 kcal a day, and it doesn't offer larger cuts.

Is 500 kcal a day less right for everyone?

No. It's a simple starting point, and your weight loss usually slows as your weight falls. For a plan that accounts for this, try the NIH's Body Weight Planner, and talk to a doctor or dietitian. If your BMI is already below 18.5, don't try to lose weight without medical advice.

Which activity level should I pick?

The first three follow the definitions in the US Dietary Guidelines, in terms of how much you walk on top of daily living. Be honest, because it's easy to overestimate. If you're unsure, start with the lower level, then adjust based on how your weight changes.

Who shouldn't use this calculator?

It's for adults, and it isn't suited to people who are pregnant or breastfeeding, whose needs are different. Anyone managing a health condition or an eating disorder should talk to a healthcare professional instead of following a calorie number from a website.

Sources

Calories at rest use the simplified Mifflin-St Jeor equation, published in 1990 from measurements of 498 healthy adults aged 19 to 78. Activity levels come from FAO/WHO/UNU and the NIH's Body Weight Planner. Calories at rest are rounded to a whole number, and daily targets to the nearest 10, because these are estimates. Individual needs vary. Read our methodology

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