# TDEE Calculator

> Your TDEE (total daily energy expenditure) is your BMR times an activity factor: a lightly active 35-year-old woman who is 165 cm and 65 kg has a Mifflin-St Jeor BMR of 1,345 kcal and a TDEE of about 1,850 kcal a day (1,345 × 1.375). Add your body fat % to compare the Katch-McArdle formula.

- Interactive calculator: https://calculatorswithsteps.com/tdee-calculator
- Category: Health & Fitness Calculators
- Last updated: 2026-11-10
- Publisher: Calculators With Steps (calculatorswithsteps.com)

## How to use the TDEE calculator

1. Choose **Metric** or **US** units and enter your sex, age, height and weight.
2. Pick the activity level that matches a normal week.
3. Optionally, add your body fat percentage. If you don't know it, the [body fat calculator](https://calculatorswithsteps.com/body-fat-calculator) can estimate it from a few tape measurements.

You get your TDEE for the level you chose, a breakdown of where those calories go, and a table of TDEE at every activity level so you can see how much moving more changes your daily burn.

## TDEE formula

TDEE is your basal metabolic rate multiplied by an activity factor:

**TDEE = BMR × activity factor**

This calculator uses the Mifflin-St Jeor equation for BMR, which a 2005 systematic review found to be the most reliable of the common equations:

**Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5**

**Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161**

If you enter body fat, it also uses **Katch-McArdle: BMR = 370 + 21.6 × lean body mass (kg)**, where lean body mass is your weight minus your fat mass.

The activity factors are 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), 1.725 (very active) and 1.9 (extra active).

## Worked example

A 35-year-old woman, 165 cm and 65 kg, with 28% body fat, who exercises 1 to 3 days a week:

- Mifflin-St Jeor BMR = 10 × 65 + 6.25 × 165 − 5 × 35 − 161 = **1,345.25 kcal**
- TDEE = 1,345.25 × 1.375 = **1,850 kcal a day**
- Lean mass = 65 × (1 − 0.28) = 46.8 kg, so Katch-McArdle BMR = 370 + 21.6 × 46.8 = 1,380.88 kcal and TDEE = 1,899 kcal

| Activity level | Factor | TDEE (Mifflin-St Jeor) | TDEE (Katch-McArdle) |
| --- | --- | --- | --- |
| Sedentary | 1.2 | 1,614 | 1,657 |
| Lightly active | 1.375 | 1,850 | 1,899 |
| Moderately active | 1.55 | 2,085 | 2,140 |
| Very active | 1.725 | 2,321 | 2,382 |
| Extra active | 1.9 | 2,556 | 2,624 |

Going from sedentary to moderately active is worth about 471 kcal a day for her, roughly the size of a typical weight-loss deficit.

## What makes up your TDEE

TDEE has four parts:

- **Basal metabolic rate (BMR):** breathing, circulation, brain and organ function. It is the largest part for most people. In the example it is 1,345 of 1,850 kcal, or 73%.
- **Thermic effect of food (TEF):** the energy spent digesting and storing food, about 10% of what you eat. Protein costs more to process than carbs or fat.
- **Non-exercise activity thermogenesis (NEAT):** walking, standing, chores and fidgeting. It varies widely between people of the same size and is the part that shrinks quietly when you diet.
- **Exercise:** planned workouts and sport.

The calculator's breakdown bar shows BMR, an estimated 10% for TEF and the rest as movement and exercise.

## BMR, RMR and TDEE

BMR is measured under strict conditions: after a night's sleep, fasting, lying still in a warm room. Resting metabolic rate (RMR) is measured with looser rules and runs slightly higher. In everyday use the two are close enough to treat as the same number. TDEE is the figure that matters for diet planning, because it is what you actually burn. The [BMR calculator](https://calculatorswithsteps.com/bmr-calculator) compares three BMR formulas side by side if you want to see the spread.

## Using your TDEE to lose or gain weight

Eat below your TDEE to lose weight and above it to gain. A deficit of about 550 kcal a day aims for 0.5 kg a week, and 500 kcal aims for 1 lb a week. For the woman above, that means about 1,300 kcal a day, close to the 1,200 kcal minimum usually advised for women, so a gentler deficit of around 275 kcal plus a little more daily walking may be easier to sustain. The [calorie calculator](https://calculatorswithsteps.com/calorie-calculator) lists targets for each rate of loss or gain, and the [macro calculator](https://calculatorswithsteps.com/macro-calculator) splits a target into protein, carbs and fat.

## How accurate is a TDEE calculator?

Equations predict the average person well but can be off by 10% or more for an individual. The activity factor is the biggest source of error because it is a self-rating. Treat your TDEE as a starting estimate: eat at it for 2 to 3 weeks, track your weight, and adjust by 100 to 200 kcal until your weight does what you expect.

## Frequently asked questions

### What is TDEE?

TDEE stands for total daily energy expenditure: all the calories you burn in 24 hours. It is your basal metabolic rate plus the energy used to digest food, everyday movement and exercise. Eating at your TDEE keeps your weight stable.

### How do I calculate TDEE from BMR?

Multiply your BMR by an activity factor: 1.2 for sedentary, 1.375 for lightly active, 1.55 for moderately active, 1.725 for very active and 1.9 for extra active. A woman with a BMR of 1,345 kcal who is lightly active has a TDEE of 1,345 × 1.375 ≈ 1,850 kcal.

### What is the difference between TDEE and BMR?

BMR is what your body burns at complete rest, just to stay alive. TDEE adds digestion, daily movement and exercise on top. In our example BMR is 1,345 kcal and TDEE is 1,850 kcal, so activity and digestion add about 505 kcal.

### Which activity level should I choose?

Choose based on a typical week, counting both exercise and your job. Desk workers who train 3 times a week are usually lightly active. If you are unsure, pick the lower level, because people tend to overestimate activity, then adjust after tracking your weight.

### Should I eat at my TDEE to lose weight?

No. Eating at your TDEE maintains weight. To lose about 0.5 kg a week, eat about 550 kcal below it; to lose 1 lb a week, eat about 500 kcal below it. A TDEE of 1,850 kcal gives a target of about 1,300 kcal for 0.5 kg a week.

### Is Katch-McArdle more accurate than Mifflin-St Jeor?

Katch-McArdle uses lean body mass, so it can suit very muscular or very lean people better, but only if your body fat figure is accurate. For most people Mifflin-St Jeor is the safer default. At 28% body fat, our example woman's TDEE is 1,899 kcal with Katch-McArdle versus 1,850 kcal with Mifflin-St Jeor.

### Why is TDEE different for men and women?

At the same weight, height and age, the Mifflin-St Jeor equation gives men 166 kcal a day more BMR than women (+5 versus −161), mainly because men carry more muscle. That gap grows when multiplied by the activity factor.

## Sources

- [Mifflin MD et al. – A new predictive equation for resting energy expenditure in healthy individuals (Am J Clin Nutr, 1990)](https://doi.org/10.1093/ajcn/51.2.241)
- [Frankenfield D et al. – Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults (J Am Diet Assoc, 2005)](https://doi.org/10.1016/j.jada.2005.02.005)

> Disclaimer: results are estimates for information and education, not medical advice. Confirm important decisions with a qualified professional.