How Many Calories Is In A Glass Of Water

Let’s get straight to the point. A glass of water—plain, clear, straight from the tap—has exactly zero calories. Seriously. Zero. Zilch. Nada.

But wait—does that mean water is a magical, weightless substance? Kind of! It’s the only thing you can drink guilt-free, anytime, anywhere. Even diet soda has a few calories (like 5–10, depending on the brand). Water? It’s the original calorie-free champion.

Why does this feel like a trick question?

Because we’re so used to everything having calories. Coffee? Yep—until you add cream. Juice? A sugar bomb. Water? It’s the boring superhero of hydration. It does its job without demanding a single calorie tax.

Fun fact: your body burns about 10 calories just to warm up a cold glass of water. That’s like eating a single potato chip—in reverse. So if you chug an ice-cold glass, you’re technically losing calories. It’s not much, but it’s a victory.

But what about “flavored” water?

Ah, now you’re trying to cheat. If you squeeze a lemon wedge? That’s about 1 calorie for a tiny squirt. A full lemon slice? Maybe 3. You’re still at almost zero—so don’t sweat it. But if you drink “vitamin water” or any of those fancy bottles? Boom. You’re looking at 50–100 calories. That’s not water—that’s a disguise.

And yes, seltzer water has zero calories. LaCroix? Zero. Club soda? Zero. Sparkling water is literally just carbonated water—unless some company adds sugar, which they sometimes do. Read the label. If it says “natural flavors” and nothing else, you’re safe.

The weird science of water and weight loss

Here’s where it gets fun. Water has no calories, but it helps you burn calories. Studies show drinking about 2 liters (8 glasses) a day can increase your metabolism by up to 30% for about an hour. That’s like a free, tiny workout—without moving a muscle.

It also fills your stomach. Have you ever eaten a huge salad and felt stuffed? That’s because water is the main ingredient. Same with water alone: drink a glass before a meal, and you’ll eat about 50–100 fewer calories. That’s like a free appetizer of “nothing.”

What about water in food?

Watermelon is 92% water. Eat a whole watermelon, and you’ve basically hydrated yourself with fewer than 1,000 calories—for a giant bowl. But a glass of actual water? It’s the only edible thing on earth that is 100% calorie-free. Not even celery (which has 6 calories per stalk) can compete.

And here’s a quirky fact: if you boiled a glass of water and then weighed the steam—you’d have zero calories. But if you froze it, you’d get ice, which is also zero calories. So whatever form water takes, it remains the ultimate freebie.

Water Calories and Nutrition (100g)

But wait—is there any water with calories?

Only if it’s contaminated. A dirty glass of pond water might have algae or bacteria, which technically have calories—but you wouldn’t drink that. Well, you might if you were a bear. But for humans, clean tap, spring, or filtered water? Zero.

And get this: even sea water has no calories. It’s just gross and salty—so don’t drink it for hydration. But if you did, you’d still get zero calories. Just intense regret.

Why this topic is secretly hilarious

Because it’s the most obvious, boring answer in the world—but people still ask! “How many calories in water?” is like asking “How many calories in air?” (Answer: also zero, unless you’re eating a cheeseburger while breathing.) It’s a trivia question that makes you sound smart at parties. “Did you know water has no calories? It’s true! Even your body burns a few just to process it.”

And if you’re counting calories obsessively, water is your best friend. You can drink a whole pitcher and your calorie count doesn’t move. It’s the guilt-free food of the universe. No other beverage can claim that. Not even black coffee (2 calories per cup, thanks to oils). Not even unsweetened tea (1–2 calories). Water is the absolute zero of the calorie world.

The final, ridiculously certain answer

A glass of water has 0 calories. Let’s repeat that: zero. No matter the size—small, big, or a massive gallon jug—it’s still zero. It doesn’t matter if it’s tap, bottled, filtered, or from a glacier. The answer never changes.

So next time someone asks you, “How many calories in a glass of water?”—just smile and say, “None. It’s the only thing in your fridge that won’t make you gain a single ounce.” And then drink a big, cold glass. You deserve it. Your body will thank you. Your calorie count won’t even blink.

P.S. If you chew ice, that’s still zero calories. But don’t chew too hard—your teeth might argue with you.