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What Does 8 Oz Water Weigh? (With Grams Pounds Ounces Chart)

In this article, you’ll learn everything you need to know about how to measure water accurately. This includes learning how to measure water, how much different volumes of water weigh, and if you can use a scale to measure this particular liquid. 

8 fluid ounces (236.6 ml) of water weigh almost exactly 8 oz, also known as half a pound (8.321 oz exactly or 0.52 pounds, or 236 grams). However, this isn’t a universal unit conversion. You can’t assume that fluid and weight ounces are the same for water as they measure different things.

How Water Is Weighed

8oz of water in a measuring cup on a scale

Water is often measured in fluid ounces or liters, which both measure volume, not weight. Though ounces are also a unit of weight in the imperial measurement system, they don’t necessarily equal fluid ounces in most cases.

To remember how much different volumes of water weigh, here is a useful table to remember.

Volume (Fluid Oz. and ml.)Grams (g)Pounds (lbs)Ounces (oz)
1 fl oz. (29.57 ml)29.57 g0.065 lbs1.04 oz  
8 fl oz. (236.6 ml)236 g0.52 lbs8.32 oz
12 fl oz. (354.89 ml)354.89 g0.78 lbs12.52 oz
16 fl oz. (473.18 ml)473.18 g1.04 lbs16.69 oz
32 fl oz. (946.35 ml)946.35 g2.09 lbs33.38
64 fl oz. (1.89 L)1,890 g (1.89 kg)4.17 lbs66.67 oz
1 gallon (3.79 L)3,785.4 g (3.79 kg)8.35 lbs133.53 oz

Why Doesn’t 1 Ounce of Water Weigh 1 Ounce?

1 ounce of water doesn’t weigh 1 ounce because they are two different measurement units that measure two different things, such as volume and weight. The difference between fluid and weight ounces is simple. Fluid ounces measure volume, the amount of space a liquid takes up. 

Instead, weight ounces measure weight. 

That means the disparity between fluid and weight ounces isn’t just limited to water. All liquids will have a difference between these two units. To make things less confusing, it’s usually specified if something is talking about fluid ounces either explicitly or with the abbreviation “fl oz.” 

Can You Weigh Fluid Ounces on a Scale?

You can weigh fluid ounces on a scale if it allows you to change the measurement unit. Most electronic scales allow you to do this. However, this might be inaccurate sometimes as it usually involves a pre-programmed weight-volume conversion that could differ depending on the type of liquid. 

Kitchen scales are most likely to have a fluid-ounce weight setting as it is most likely that you will need to convert to liquid conversions in cooking. However, the density and type of liquid will change this weight-volume ratio.

For example, 1 oz of water weighs a different amount than 1 oz of oil. 

If you are able to memorize how much different volumes weigh or convert volume to weight for a particular liquid, then you can use that as a guide if you want to measure fluid ounces using a scale.

In this case, make sure to subtract the weight of your container from the net weight of your liquid. You should note that if you wish to calculate this conversion yourself, you’ll also need to know the density of the liquid you’re converting. 

Here is the formula: Mass = Density x Volume

A scale will work if you have no other options. If you want to accurately measure fluid ounces, you should use a marked container or measuring cup of some sort.

Precise weighing of a glass of water on kitchen scale for cooking

How To Measure 1 Oz of Water?

There are multiple ways to accurately measure 1 oz of water, depending on the type of oz you want to measure. 

You can measure 1 oz of water by using a measuring container that has units marked on the side. You can measure 1 ounce of mass using a scale like you would with non-liquid items.

Measuring 1 Oz of Water in Volume

If you want to measure 1 fluid ounce of water, then the easiest way to do so would be to use a measuring cup or another type of container that has imperial units marked on it. You can also use a measuring container that has milliliters marked if you remember. 

The conversion of 1 fl oz is equal to 29.57 ml. 

You can use this as your base conversion for any other fluid ounce measurements if you multiply your fluid ounces by 29.57 to get your milliliter total. You can also measure 1 fluid oz of water by using the calculation if you know the mass and the density of your liquid by using the equation Volume = Mass / Density.

Measuring 1 Oz of Water in Weight

If you want to measure 1 oz of water in weight, there is also a simple way to do so. 

  1. If you own a scale, weigh the container you plan to use and either zero out the scale’s weight to not count the container or make a note of it so you can subtract it from your total.
  2. Make sure you have your scale set to ounces if you’re using an electronic scale or keep an eye on the ounce measurements on an analog scale.
  3. Slowly pour water into your container until your weight shows 1 oz. 

However, you can also measure 1 oz of weight if you know the volume of your water. You can do this through the formula Mass = Density x Volume.

You can also simply remember that 1 oz of water in weight is equal to 0.96 fl ounces (28.35 ml).

In this case, you can simply measure out the volume of water equivalent to the weight you want. 


You might assume that fluid and weight ounces are the same because they use the same term. However, they mean two very different things. That means you can’t use these terms interchangeably because 1 fluid ounce doesn’t equal 1 weight ounce. 

To measure fluid ounces of water, it’s best to use a measuring cup to measure volume, while to measure weight ounces of water, you can use a scale.

For more, don’t miss How Much Emergency Water Should I Stockpile and Store Per Person?