Yes, and more than most people guess: a night costs somewhere between 300 and 500 calories. For a lot of us that is the single largest uninterrupted block of energy use in the day. Your heart, lungs, kidneys and brain do not clock off, and keeping them running has a price.
Where those calories go
Sleep burn is basal metabolism, more or less. Breathing, circulating blood, maintaining body temperature, filtering waste, repairing tissue. The brain alone is expensive to run and stays busy through the night.
The rate is a little below your daytime resting rate, though not dramatically. If you want a rough figure for yourself, take your BMR from the TDEE calculator, divide by 24 to get an hourly rate, and multiply by however long you actually sleep. It will be an estimate, but it will be closer to your own body than any generic 300 to 500 range.
What changes the number
Size is the biggest lever. A larger body has more tissue to maintain, so it burns more doing nothing.
Muscle costs more to keep than fat does, which is why two people at the same weight can have different overnight totals. The difference is real but smaller than the fitness industry likes to claim, and building muscle is worth doing for reasons far better than the handful of calories it adds while you sleep.
Age lowers it gradually. Room temperature moves it a little, since a cool room makes your body work harder to hold its temperature. Hormones matter, particularly thyroid function.
Sleep quality matters more than the burn
This is the part worth your attention, and it is not really about calories.
Short or broken sleep changes appetite. Hunger signalling shifts, cravings for quick carbohydrate get louder, and self-control over food is lower on a bad night's sleep than a good one. The effect is big enough to sabotage a careful deficit.
Sleep is also when repair happens. Train hard and sleep badly and you get most of the fatigue with a fraction of the adaptation. Anyone trying to hold muscle through a cut should treat sleep as part of the programme rather than as time off from it.
You cannot game it
There is a genre of advice about boosting overnight calorie burn: sleep cold, eat protein before bed, take this supplement. The honest answer is that the effects range from tiny to imaginary.
A cool room may add a small amount. Protein before bed has a modest digestive cost and may help with overnight muscle repair. Neither is going to move your weekly total in a way you would notice.
What does move it is having more muscle and being bigger, and neither is an overnight trick. If you want something you can actually push on, what you eat and how much you move during waking hours are worth far more attention.
Why it still matters
Because it explains where most of your energy actually goes. People are often surprised that formal exercise is the smallest slice of their day's burn while basal metabolism is the largest.
That is a useful thing to internalise. It reframes a missed gym session as a minor event, and it makes clear why chasing exercise to outrun a poor diet fails so reliably. Your body is spending most of the budget on simply existing, and it does that whether or not you turn up to train.
Sleep well because it fixes your appetite, your training and your mood. The calories burn themselves.