TDEE CALCULATOR BMR ACTIVITY LEVELS FAQ SPUNK.BET

Calories and energy needs BMR, TDEEand activity levels

Updated October 28, 2026

Your daily calorie need has two parts: the energy your body burns to stay alive, and the energy you spend moving.

The Dietary Guidelines for Americans 2020-2025 (USDA and HHS) estimated that adult women need about 1,600 to 2,400 calories a day and adult men about 2,000 to 3,000. Your own number depends on your age, size and activity.

Calculate my TDEE How it works

TDEE Calculator

Enter your age, weight and height to see your BMR and TDEE.

Results are estimates, not measurements. BMR uses the Mifflin-St Jeor equation (1990); the activity multipliers are a common convention, not part of that paper. Educational tool, not medical advice. Nothing you type leaves your browser.

THE BASICS

What a calorie is, and what BMR means

The "calorie" on a food label is a kilocalorie (kcal). One kcal equals 4.184 kilojoules (kJ).

Basal metabolic rate (BMR) is the energy your body uses at complete rest to run your organs and keep your temperature stable. For most people it is the largest part of daily energy use. Resting metabolic rate (RMR) is a close relative measured under less strict conditions, and most people use the two terms interchangeably.

BMR rises with body size and falls slowly with age. At the same weight and height, men usually have a higher BMR than women, mainly because they carry more lean mass on average.

THE EQUATION

The Mifflin-St Jeor equation (1990)

In 1990, Mifflin, St Jeor and colleagues measured the resting energy expenditure of 498 healthy adults aged 19 to 78 and published a prediction equation in the American Journal of Clinical Nutrition. A 2005 systematic review (Frankenfield and colleagues, Journal of the American Dietetic Association) found it the most reliable of the common equations. W is weight in kg, H is height in cm and A is age in years:

Men:   BMR = 10 × W + 6.25 × H − 5 × A + 5
Women: BMR = 10 × W + 6.25 × H − 5 × A − 161

Example: a 30-year-old man who weighs 82 kg and is 180 cm tall has a BMR of 820 + 1,125 − 150 + 5 = 1,800 kcal per day.

Muscle mass and health conditions are not in the formula, so treat the result as a first estimate.

FROM BMR TO TDEE

TDEE and activity levels

Total daily energy expenditure (TDEE) is everything you burn in a day: BMR, digestion, exercise and all other movement. The simplest estimate multiplies BMR by an activity factor:

Sedentary: x1.2

Desk work and little planned exercise.

Light to moderate: x1.375 to x1.55

Exercise on 1 to 5 days a week.

Active: x1.725 to x1.9

Hard training most days, or a physical job.

These factors are a rough convention. The step from "moderate" to "active" adds about 11% to the estimate, so pick the level that matches a normal week, not your best week.

The CDC, following the Physical Activity Guidelines for Americans (2nd edition, 2018), recommends at least 150 minutes of moderate-intensity aerobic activity a week plus muscle-strengthening activity on 2 or more days.

Bar chart of TDEE by activity level for a 30-year-old man, 82 kg, 180 cm, with a Mifflin-St Jeor BMR of 1,800 kcal per day: sedentary 2,160, light 2,475, moderate 2,790, active 3,105, very active 3,420 kcal per day
The same body can need 2,160 or 3,420 kcal per day: the activity multiplier alone moves this estimate by 1,260 kcal.
USING YOUR NUMBER

How to use a TDEE estimate

Very low-calorie diets of about 800 calories a day or less are meant to be supervised by a health care professional, according to the NIH's National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). If you are pregnant, under 18 or ill, ask a doctor or dietitian for a personal target.

FAQ

Common questions

What is the difference between BMR and TDEE?

BMR is the energy your body uses at complete rest. TDEE is BMR plus the energy you use to digest food and to move, so TDEE is always higher.

How accurate is the Mifflin-St Jeor equation?

It predicts an average from 498 healthy adults aged 19 to 78 (Mifflin et al., 1990). An individual can be off by 10% or more, so adjust it with real weight changes over several weeks.

Does eating 500 calories less per day mean losing exactly one pound per week?

Not exactly. NIH research (Hall and colleagues, The Lancet, 2011) showed that energy expenditure falls as weight falls, so the fixed 3,500-calories-per-pound rule overestimates long-term loss. The NIH Body Weight Planner models this change.

Which activity level should I choose?

The level that matches a normal week. If unsure, pick the lower level.

Sources: Mifflin MD, St Jeor ST, et al., American Journal of Clinical Nutrition, 1990. Frankenfield D, et al., Journal of the American Dietetic Association, 2005. Hall KD, et al., The Lancet, 2011 (NIH). NIDDK. CDC, Physical Activity Guidelines for Americans, 2nd edition, 2018. USDA and HHS, Dietary Guidelines for Americans 2020-2025.