Sleep Calorie Calculator

Find out how many calories you burn while sleeping.

Your Weight

Sleep Duration

ADVANCED SETTINGS (OPTIONAL)
expand/collapse

Include your height, sex, and age for a more accurate estimate.

Your Height:

Sex:

Calorie Burn & Sleeping

Introduction

This simple calculator allows you to estimate calorie and fat burn while you're sleeping.

Sleep is one of the least active things we do. However, the typical adult needs 7 to 9 hours of sleep per night, during which time they will burn 52–76 kcal (218–317 kJ) per hour, so calorie burn while sleeping accounts for a significant chunk of our daily energy needs.

As with all activities, heavier people typically burn more calories, although individual metabolism will vary.

How It Works

Basic Calculation (METs)

The basic version of the calculator is based on sleep duration and body weight and uses METs to predict calorie burn. MET is the acronym for Metabolic Equivalent of Task, and METs provide a straightforward way to determine the energy needed for an activity. Used in conjunction with activity duration and a person's body weight they are widely used to estimate calorie burn.

One MET is approximately the energy required to sit down and do nothing (or to sleep), and MET values for other activities are determined with reference to this baseline. As an example, walking at 4 mph (~6.4 kph) requires roughly 5.5 times as much energy as doing nothing, so the MET value for walking at this speed is 5.5.

METs and Calorie Conversion (kcal)

Converting from METs to Calories (kcal) is carried out as follows:

kcal = METs × W × T

where:

W = Weight in kilograms
T = Time in hours

For example, the Calories/kcal needed for a 4 MET activity carried out for 3 hours by a person weighing 85 kilograms is:

4 × 85 × 3 = 1,020 kcal

Sleeping METs

The 2024 Compendium of Physical Activities List for Inactivity assigns a MET value of 1.0 to sleeping.

Sleeping vs. Other Restful Activities

The Compendium lists 17 activities under "inactivity". Here's a summary of those activities and how they compare to sleeping.

Activity MET Value Difference
Sleeping 1.0 =
Lying quietly or meditating 1.0 =
Sitting quietly 1.0 =
Sitting smoking 1.2 +2
Sitting and listening to music or watching a movie 1.2 +2
Sitting at a desk 1.3 +3
Sitting and fidgeting feet 1.8 +8
Standing quietly or watching television 1.3 +3
Standing and fidgeting 1.5 +5
Reclining and reading or talking 1.3 +3
Reclining and writing 1.5 +5

So, the most "active" inactive thing you can do is sit and fidget your feet, which burns 1.8 times as many calories as sleeping.

If you're keen to use METs to work out calorie count for almost any activity from the compendium then see our MET calorie calculator.

Advanced Calculation (Mifflin-St Jeor)

One study, which analyzed data from over 11,000 adults, found that the average resting metabolic rate of adults is lower than suggested by the traditional 1 MET. Rather the true average resting rate for adults is closer to 0.84.

With this in mind, the advanced version of the calculator uses your body weight, height, sex, and age to first determine your Basal Metabolic Rate (BMR). Simply put, your BMR is the number of calories you need to carry out the bodily functions necessary to live while at rest. It is typically expressed in Calories (kcal) per 24 hours.

To calculate BMR we use the Mifflin-St Jeor equation, which offers variants for men and women.

For women:

BMR = (10 × W) + (6.25 × H) − (5 × A) − 161

For men:

BMR = (10 × W) + (6.25 × H) − (5 × A) + 5

where:

W = Weight in kilograms
H = Height in centimeters
A = Age in years

From there we can then use BMR to determine the calories burned while asleep.

Sleep Burn =
BMR 24
× hours

Sleeping Fat Burn Calculation

One pound of fat represents roughly 3,500 Calories (32,284 kilojoules) of energy:

Pounds =
Calories 3,500

Using metric values:

Kilograms =
kilojoules 32,284

For example, a 200-pound / 90.7-kilogram person sleeping for 8 hours will burn through roughly 726 kcal / 3,038 kJ, meaning they would lose roughly:

726 3,500
≈ 0.21 lb

or in metric:

3,038 32,284
≈ 0.09 kg

Using the Calculator

Form Fields

Weight

Enter your weight in pounds, kilograms, or stones and pounds. More weight means greater energy requirements and therefore greater calorie and fat burn.

Sleep Time

Specify how long you slept in hours and minutes.

Height (advanced only)

Enter your height in either feet and inches or centimeters.

Sex (advanced only)

Specify male or female.

Age (advanced only)

Enter your age as a whole number. Accepted ages are 18 to 100.

Example Results

Results include details of overall calorie burn, calorie burn per hour, fat burn, and a summary table.

Basic Results

Assuming a person weighing 180 lb / 81.6 kg sleeps for 9 hours:

Calorie burn: This 9h sleep burns roughly 735 kcal / 3,075 kJ of energy, which works out to 82 kcal / 342 kJ per hour.

Fat burn: This calorie burn represents approximately 0.21 lb / 0.10 kg of fat loss.

Summary
Sleep Time
9h
Energy Requirements
Calories (kcal) 735 kcal
Kilojoules 3,075 kJ
Fat Loss (estimate)
Pounds 0.21 lb
Kilograms 0.10 kg
Compendium Details
Activity Sleeping
Code 07030
METs 1.0
Your weight
Kilograms 81.6 kg
Pounds 180 lb
Stones & Pounds 12 st 12 lb

Advanced Results

Assuming the same woman, a 34-year-old, weighing 180 lb (81.6 kg) at a height of 5 ft 6 (167.6 cm), sleeps for 9 hours:

Calorie burn: This 9h sleep burns roughly 575 kcal / 2,406 kJ of energy, which works out to 64 kcal / 267 kJ per hour.

Fat burn: This calorie burn represents approximately 0.16 lb / 0.07 kg of fat loss.

Summary
Sleep Time
9h
Energy Requirements
Calories (kcal) 575 kcal
Kilojoules 2,406 kJ
Fat Loss (estimate)
Pounds 0.16 lb
Kilograms 0.07 kg
Your weight
Kilograms 81.6 kg
Pounds 180 lb
Stones & Pounds 12 st 12 lb
Your Age
34
Your Height
Centimetres 167.6 cm
Feet & Inches 5 ft 6 in

Basic Calculator vs. Advanced Calculator

Note that the basic calculator estimates a calorie burn of 735 kcal (3,075 kJ) versus 575 kcal (2,406 kJ) for the advanced calculator.

That's a difference of 160 kcal (669 kJ).

Certainly, the advanced calculator's prediction is more in line with contemporary resting metabolic rate estimates, such as the 0.84 kcal/kg/hour mentioned in the study above. In fact, if we replace the MET value of 1, as provided by the Compendium of Physical Activities, with 0.84, we get:

0.84 × 81.6 × 9 = 617 kcal

Which is much closer to the advanced calculator's estimate.