Does Farting Burn Calories?
It's one of the internet's favourite feel-good rumours: that every fart torches a handful of calories, so you could practically diet by passing gas. It's a lovely idea. It's also, sadly, not true. Here's the honest answer, the actual maths, and why the myth refuses to die.
The Short Answer
No — farting does not burn a meaningful number of calories. Passing gas mostly involves relaxing a muscle (the anal sphincter) to let pressure escape, rather than contracting muscles hard the way exercise does. The energy your body spends doing that is so small it can't be measured in any practical way, and certainly won't show up on a scale or a fitness tracker.
Where the Myth Came From
A few years ago a claim spread across social media that a single fart burns around 67 calories, and that farting 52 times a day could burn off an entire pound of fat. The numbers were completely made up — there was never any study behind them — but they were funny and oddly believable, so they stuck. Like most viral health "facts", the story travelled far faster than the correction.
What Actually Happens When You Fart
A fart is just trapped gas leaving your digestive system. That gas comes from two places: air you swallowed while eating and drinking, and gas produced when bacteria in your colon ferment food you didn't fully digest. When enough pressure builds up, the sphincter relaxes and the gas escapes. (If you want the physics of why it makes noise, we cover that in why do farts make noise?)
The key point: this is a release of pressure, not a workout. Compare it to letting air out of a balloon versus inflating one. Letting gas out takes almost no effort, so it burns almost no energy.
Do Farts Have Calories?
No. Calories are a measure of food energy your body can absorb and use. A fart is a blend of gases — mostly nitrogen, hydrogen, carbon dioxide, oxygen and sometimes methane — none of which your body digests for energy. There is nothing in a fart for your body to "spend", so a fart carries zero usable calories.
Does Farting Make You Lose Weight?
Technically, releasing gas removes a tiny amount of mass — but we're talking a fraction of a gram, and your body is constantly producing more gas to replace it. Any change on the scale would be far too small to see and instantly reversed. So while you do momentarily lose a sliver of weight, it has nothing to do with losing fat, which is what people mean by "losing weight". We run the full numbers in does farting make you weigh less?
What Does Burn Calories Around Digestion
There's a grain of truth nearby. Your body genuinely does spend energy digesting food — this is called the thermic effect of food, and it accounts for roughly 10% of your daily calorie burn. Protein in particular takes more energy to process than fat or carbs. But that energy is spent on digestion itself — breaking down, absorbing and storing nutrients — not on the fart at the end of the line. The fart is just the exhaust, not the engine.
The Bottom Line
Farting doesn't burn calories, farts don't contain calories, and you can't pass-gas your way to weight loss. It's a fun myth with zero science behind it. If you're after real calorie burn, a brisk walk will do far more — and, conveniently, walking also helps move trapped gas along, so you might just get a fart out of it too. For more myth-busting and genuine science, see our fart facts page, and for the dietary side of gas, our guide to foods that make you fart.
This article is general information and not medical advice.