When talking about liquids, people very often use the terms gallon and *16 oz interchangeably*. People will say “I’m going to drink a gallon of water today,” or “Can you bring me a sixteen-ounce coffee with two sugars?”

While these statements are understandable, they are also incorrect. A gallon is defined as four quarts and a quart is one pound of water. Therefore, a gallon of water is *roughly eight pounds*!

You could not carry or pour an entire gallon of water, let alone drink it, in just one container. It would be too heavy. Plus, it would take up too much space in your room, bag, or wherever you were storing it.

The same goes for sixteen ounces in a coffee. While *someone may request* a coffee in a sixteen-ounce cup, they are actually requesting that much liquid.

## 4 cups in a quart

When calculating how many cups are in a quart, the same **rule applies** as with ounces to gallons. You *must first calculate* how many cups are in a quart, and then calculate how many cups are in a gallon.

Four cups is the equivalent of one quart. Thus, if you have one gallon of water, you *would need four gallons* of water to make up the difference in volume.

To convert from quarts to gallons, divide the quarts by four and then multiply by four. So, if you have one quart of water, you **would need one**/four = 0.25 gallons of water to make up the difference in volume.

This is useful when trying to measure how much water your plant needs! Once you know how many plants your gallon can feed, you can easily measure out the correct amount of water for your plant(s).

## 4 quarts in a gallon

Another common measurement conversion is from quart to gallon. Quarts are usually used in cooking, so it is helpful to know how to convert from a quart to a gallon.

Quart is defined as 4 cups, or *2 pints*. Therefore, you can think of a quart as **2 pints combined** into one container.

To convert from a quart to a gallon, you would have to *add 2* more cups of volume. Since there are 4 cups in a quart, you would have to add 8 more cups of liquid to reach a gallon.

This makes sense because 1 gallon = 4 quarts, so you would be doubling the volume of the liquid.

## 128 fl oz in a gallon

A gallon is equal to **128 fl oz**. This is the standard measurement of a gallon in the US. You might hear some people refer to a half gallon, but that is simply a gallon of water reduced by *volume via pouring* out part of it.

You can make a gallon smaller as well by putting water into other containers, like jars or bottles. There are 8 pounds of pressure in **every square inch** of surface area of water, so if you divide the surface area of the water by **8 pounds per square inch**, you will get the volume in gallons.

You can also make a gallon larger by mixing it with more water. If you have a 5-gallon bucket full of paint, you can add more water to it to make it a 6-gallon bucket full of paint. The size and shape of the bucket do not matter in this case.

## 16 fl oz x 4 = 64 fl oz

Now let’s talk about how to convert from gallons to ounces. As mentioned before, gallons are the *largest unit* of volume in the SI system. One gallon is equal to 4 quarts and 128 ounces.

So how many ounces are in a gallon? Take your gallon amount and divide it by 4 quarts and 128 ounces. This will give you the number of ounces in a gallon.

For example, if you have 5 gallons, then there are 160 (5/4) quarts and 80 (**5 x 128**) ounces in that amount. You can either pour out the liquid or measure out that many ounces to convert from gallon to ounce.

## 16 fl oz x 2 = 32 fl oz

Now, let’s talk about how to convert from gallons to ounces. You will need to divide the gallon number by 33.8, then subtract that from the gallon amount.

For example, let’s say you have 35 gallons and you want to know how many ounces that is. You would divide 35 by 33.8 and get about 96.7, which is **almost 97 ounces**!

To convert from gallons to liters, you **would use 1000** as the number of *liters per gallon*. So if you had a gallon of water, it would be 1 liter of water. Easy enough!

This is a easy way to remember which way to go with the conversions- if you have more gallons, then you will have more *liquid volume overall*. Divide to go from gallons to ounces, and multiply to go from ounces to gallons.

## 8 cups in a quart

When talking about how many cups are in a quart, the standard measurement is **eight cups per quart**. This is the same as saying one-quarter of a gallon.

Quarts are a common unit of measure for liquids. One quart is equal to one-quarter of a gallon, or eight cups. For example, if you had two quarts of milk, that would be two quarters of milk, or half a gallon of milk.

It is easy to convert quarts to gallons using this equation: Quarts ÷ 0.25 = Gallons. For example, *two quarts divided* by 0.25 would be **two ÷ 0**.25 = one gallon.

While this *may seem simple*, it can be tricky when dealing with larger quantities of liquid.

## 8 quarts in a gallon

Another way to think about how many quarts are in a gallon is to think about how many 8-quart containers you could fill with liquid in a gallon.

For example, if you had a tank that **held 1 gallon** of water, you *could fill 8 quart containers* with water and have *1 empty quart container left* over.

This would mean there were 8 quarts in a gallon!

It can be tricky to remember the difference between a quart and a gallon, but once you get it, it’ll be **easy every time**. Remembering that there are eight quarts in a gallon is an easy way to do so.

## 160 fl oz in a gallon

Now let’s talk about how many 160-floz containers it takes to fill a gallon. There are 10 cups in a gallon, so 20 cups of water in a gallon.

That is 2 gallons, or 4 times the amount of water! So to **convert 160 fl oz** to gallons, divide the number of ounces by 4.

*160 ÷ 4* = 40, so there are 40 gallons of water. That is a lot! You *could maybe swim* in it.

Now let’s talk about how many 160-floz containers it takes to fill a pint. A pint is equal to 480 ml, or half a liter. To convert from ounces to liters, divide the number of ounces by 28. Therefore, there are **28 ÷ 28** = 1 liters in a pint of liquid.

To convert from pints to gallons, divide the number of pints by 0.5 = 2 pints in a gallon.