How much calories burn in 1 glass of water?

Water (without additives like flavor or sugars) has ZERO caloric content.

For your average 8 oz serving of (tap) water you have

0 calories

0 fat

0 cholesterol

0 carbohydrates

0 protein

0 vitamin A

0 vitamin C

0 Iron (at least you're not supposed to be getting iron, however its been known to happen via old piping)

You may however get as much as 7 mg of sodium and 1% calcium nutritionally.