Calories Burned Sleeping Calculator

Calories burned sleeping is the energy your body uses while you sleep. Your heart keeps beating, you keep breathing, your brain stays active, and your body holds its temperature and repairs tissue. This calculator estimates that energy from your basal metabolic rate (BMR), the calories your body uses at complete rest.

What the Sleeping Calorie Estimate Measures

The result is the total energy used during your time asleep. It is not extra energy on top of resting, because sleep is a resting state. It also does not track your sleep stages, heart rate, or room temperature. It is an estimate based on body size and age, not a measurement.

The Formula

BMR (men) = 10 x weight (kg) + 6.25 x height (cm) - 5 x age (years) + 5

BMR (women) = 10 x weight (kg) + 6.25 x height (cm) - 5 x age (years) - 161

Calories burned sleeping = (BMR / 24) x hours asleep

The BMR equation comes from Mifflin and St Jeor, the same one used on our BMR and TDEE calculators¹. In a respiration chamber study, the energy young adults used overnight matched their BMR on average (a ratio of 1.00), so the tool applies no extra adjustment².

How This Calculator Computes Your Result

Enter your sex, age, height, weight, and the time you were asleep. You can use pounds and feet and inches, or kilograms and centimeters. The tool converts to metric, works out your BMR, divides it by 24 to get calories per hour, and multiplies by your hours asleep. It rounds the total to the nearest 5 kcal and the hourly figure to the nearest 1 kcal.

The result card also shows:

• A likely range, from 5% below to 6% above the main figure. This spans the average results of the sleep studies below² ³.

• A comparison using the 2024 Compendium of Physical Activities, which lists sleeping at 1.0 MET (code 07030)⁴. That method multiplies 1.0 by your weight in kilograms and your hours asleep.

• A table of your calories for 6, 7, 8, and 9 hours of sleep.

• If you choose an activity level (optional), your estimated total daily energy expenditure (TDEE) and the share of it used during sleep.

Enter time actually asleep, not time in bed. Naps work too.

What Your Result Means

Your result is the energy your body needed to run itself overnight. Bigger, taller, and younger bodies use more. Here is what two example adults burn:

That works out to roughly 55 to 70 kcal per hour for these two people. If you pick an activity level, the tool shows what share of your day sleep takes up. For 8 hours of sleep, that share depends only on your activity level:

Why Sleep Burns About the Same as Your BMR

You might expect sleep to burn much less than BMR, since BMR is measured awake. Respiration chamber studies show the two are close, but not identical. In one study, overnight energy use matched BMR in young adults (ratio 1.00), ran about 6% higher in older adults, and about 8% lower in children². An earlier study of 40 lean adults found overnight energy use averaged 5% below BMR, and the lowest point of the night was about 12% below³. Over a full 24 hours, the authors found this gap made almost no difference³.

Because the studies do not agree on one number, this calculator treats sleep as equal to BMR and shows the spread as a range. The Compendium comparison often reads higher. It assumes one standard resting rate per kilogram for everyone, which can overstate a person's true resting rate, with larger errors in people who are overweight, older, or women⁵.

Does REM Sleep Burn More Calories?

A little, but the tool does not need your sleep stages. In a room calorimeter study of 29 adults, energy use was lowest in deep (slow-wave) sleep, higher in REM sleep, and highest during brief awakenings⁶. Energy use dropped soon after falling asleep and began to rise before waking⁶. Another lab study found only small differences between stages, while time spent awake during the night raised energy use⁷. So a restless night may burn slightly more, but stage mix changes the total by little.

Why Sleeping More Is Not a Weight Loss Strategy

An extra hour in bed burns about one more hour of BMR, which you would also burn lying awake. The Compendium lists sleeping and lying quietly awake at the same 1.0 MET⁴. In fact, staying awake costs more. In one lab study, a night without sleep raised energy use that night by about 32% compared with sleeping⁷.

The catch is appetite. When 16 adults had their sleep cut short for five days in a lab, their daily energy use rose about 5%⁸. But they ate more than that extra energy, especially after dinner, and gained an average of 0.82 kg (about 1.8 lb)⁸. So the link between sleep and weight runs through eating, not through calories burned in bed.