# Calorie calculator

> A calorie calculator estimates how many calories you burn in a day: Mifflin-St Jeor BMR multiplied by an activity factor from 1.2 to 1.9. A 30-year-old man who is 5 ft 11 in and weighs 180 lb, with moderate activity (1.55), burns about 2,788 calories a day. A workout adds MET × weight in kg × hours.

Source: https://www.calterix.com/en-us/calculator/calorie/ · Updated 11/06/2026 · en-US

## How daily calorie burn is calculated

Daily burn has two parts: **BMR**, the energy your body uses at rest, and the energy you spend moving. The calculator finds BMR with the Mifflin-St Jeor formula, then multiplies by an activity factor. The [BMR calculator](https://www.calterix.com/en-us/calculator/bmr/) shows every formula in detail.

```
Daily burn = BMR × activity factor
BMR (men) = 10 × kg + 6.25 × cm − 5 × age + 5
```
Example: 180 lb (81.6 kg), 5 ft 11 in (180.3 cm), 30 years, moderately active. BMR = 1,799. Daily burn = 1,799 × 1.55 = 2,788 calories.

| Activity level | Factor | Daily burn with a BMR of 1,800 |
| --- | --- | --- |
| Sedentary (little or no exercise) | 1.2 | 2.160 calories |
| Lightly active (exercise 1 to 3 days a week) | 1.375 | 2.475 calories |
| Moderately active (3 to 5 days a week) | 1.55 | 2.790 calories |
| Very active (6 to 7 days a week) | 1.725 | 3.105 calories |
| Extra active (hard training or a physical job) | 1.9 | 3.420 calories |

Common factors. They are approximations.

## Calories burned in workouts

The workout estimate uses the **MET**, a number that compares the effort of an activity with resting (1 MET). Calories = MET × weight in kg × hours. A 155 lb person (70.3 kg) who walks for an hour at 3 mph (3.5 MET) burns about 246 calories.

| Activity | MET | Calories in 1 hour at 155 lb |
| --- | --- | --- |
| Walking, 3 mph | 3,5 | 246 calories |
| Brisk walking, 4 mph | 5,0 | 352 calories |
| Running, 5 mph (12-minute mile) | 8,3 | 584 calories |
| Running, 6 mph (10-minute mile) | 9,8 | 689 calories |
| Leisure biking, under 10 mph | 4,0 | 281 calories |
| Moderate biking, 12 to 14 mph | 8,0 | 562 calories |
| Swimming laps, moderate effort | 5,8 | 408 calories |
| Weight training, light to moderate | 3,5 | 246 calories |

Approximate values from the Compendium of Physical Activities. Real burn changes with fitness, terrain, and technique.

Fitness watches and gym machines often show other numbers because they use other models. Treat any estimate as a ballpark.

## How to use the numbers

- Estimated burn helps you see energy balance, but real burn can differ by 10% to 15% from person to person.
- Pregnancy, nursing, under 18, and metabolic conditions come with their own needs.
- For a weight goal, talk with a doctor or registered dietitian. The [calories to lose weight calculator](https://www.calterix.com/en-us/calculator/calorie/calories-to-lose-weight/) shows the limits of a moderate deficit.

To find the weight range for your height, see the [BMI calculator](https://www.calterix.com/en-us/calculator/bmi/) and the [ideal weight calculator](https://www.calterix.com/en-us/calculator/ideal-weight/).

## Frequently asked questions

### How many calories should I eat a day?

It depends on age, sex, size, and activity. The Dietary Guidelines for Americans put adult needs at roughly 1,600 to 2,400 calories for women and 2,000 to 3,000 for men. The calculator gives your own estimate.

### How do I calculate how many calories I burn a day?

Find BMR with the Mifflin-St Jeor formula and multiply by an activity factor from 1.2 to 1.9. A 30-year-old man at 180 lb and 5 ft 11 in with moderate activity burns about 2,788 calories.

### How many calories does a workout burn?

Multiply the activity MET by your weight in kilograms and the hours spent. Running 5 mph for 45 minutes at 180 lb: 8.3 × 81.6 × 0.75 = 508 calories.

### How many calories does walking burn?

At 3 mph (3.5 MET), a 155 lb person burns about 246 calories an hour. At a brisk 4 mph (5.0 MET), the burn rises to about 352 calories an hour.

### What is the difference between BMR calories and daily calories?

BMR calories are what the body burns at rest. Daily calories add movement and exercise on top. The calculator shows both parts side by side.

### Does this calorie calculator count the calories in food?

No. The tool estimates calories burned, not the calories in a meal. For food, check the Nutrition Facts label, which bases the Daily Value on a 2,000 calorie diet, or the USDA FoodData Central database.