How Much Does Water Weigh?

There are many reasons one might wonder about just how much water weighs. This article has all the info you might need about how much water weighs.

This article may contain affiliate links where we earn a commission from qualifying purchases.

There are many reasons one might wonder about just how much water weighs. Perhaps you are packing your backpack for a long hiking trip and are wondering just how much water you are going to have to carry around with you for the next few days.

Perhaps you are curious about why it is so important to bail water out of your boat should it become flooded. Whatever your reason, you have come to the right place. This article has all the info you might need about how much water weighs.

Table of Contents

How much does water weigh?

Water weighs approximately 8.3 pounds per gallon but can be as much 10 pounds. The reason being that several factors can affect the weight of water, primarily the atmosphere and the temperature. For example, in extreme temperatures such as above 2000 degrees Fahrenheit a gallon of water can weigh 0.3 pounds less. In very cold temperatures (but still above freezing) water can weigh as much as 10 pounds. This is because the water particles are not vibrating as much.

It is important to note that a gallon is a unit of volume not weight, so a gallon of hot water would be less water overall than a gallon of cold water. As the particles are vibrating far more quickly.

When it comes to atmosphere, we must also consider gravity. The higher the gravitational pull the more the water will weigh. For example, water on the moon will weigh less than it does on earth because gravity is far less. Conversely, water on Jupiter will weigh more as Jupiter has a stronger gravitational pull than the earth.

Water’s weight in the metric system is very interesting

Whether you believe that America should follow the rest of the world’s lead and convert to the metric system is up to you to decide. What shouldn’t be up for debate is how much better the metric system is at handling water and its weight. In the metric system, liquids are measured in liters and the weight of things is measured in kilograms. 1 kilogram is 1000 grams and 1 liter is 1000 milliliters. Simple.

When it comes to water this works wonderfully. 1 liter of water weighs 1 kilogram. Of course, things can affect the weight as mentioned above but for the most part, it is a pretty accurate 1:1 ratio. This means you can look at any quantity of water and know exactly how much it weighs. 452 milliliters of water will weigh 452 grams. And so on, it is a far superior way of measuring liquids (especially water).

Does ice weigh more or less than water?

If you are trying to directly compare the weights of water and ice it can be pretty tricky. You might not have considered just how much the weight can change, after all, ice is just very cold water. Of course, you know that ice is water in its frozen state, what you might not know is that this interestingly lowers the weight of the water. Ice weighs marginally less than water because it is less dense.

If you are trying to measure an 8oz bottle of water, you might weigh the bottle first and then weigh it once it is full. Doing this allows you to know how much the water alone weighs. If you were to do the same thing and then freeze the bottle, you would be in for a bad time. If the bottle was full it would burst. This means to fill the bottle with ice you would have to only partially fill it with water.


Hopefully, this article has answered any questions you may have had about water and how much it weighs. As mentioned above, water can weigh far more or far less depending on where in our solar system you are. It can also change based on temperature. However, for you, the weight of water is likely going to be pretty constant. The metric system has very cleverly found a way to make a formula that works for measuring water’s weight exactly. If you were wondering how much water weighs because you are going to be carrying it for long distances, you should know that the average person must drink 1/2 a gallon a day. This is going to be about 4-5 pounds.

Recent Articles

Subscribe To Our Newsletter

Thank you! You're signed up for our free newsletter!

Oops! Something went wrong while submitting the form