People who grew up in the United States are usually relatively familiar with the size of a gallon. However, estimating a large number of gallons can be tricky, and it can also be difficult to get a feel for how much a gallon is if you are from a part of the world that uses liters instead. Learning about a few common examples can help you get a better feel for just how big a gallon is.
Milk and Water
Gallons are a measurement of volume. One gallon is equal to about 3.785 liters. Outside of the United States, most liquid measurements are given in liters, but in the U.S., liquid measurements are usually explained in gallons.
This means that common household items such as milk are sold by the gallon. You can also purchase milk by the half-gallon or quart, which is 1/4 of a gallon.
Water is another great example. Purified water is often sold by the gallon, and you can buy it in single-gallon containers that look much like plastic milk jugs.
However, you can also purchase water in larger containers. For example, an office water cooler might hold a 3 or 5-gallon water container.
Fuel
Fuel, most commonly gasoline, is also sold by the gallon. The price for a single gallon of gas will be printed near the gas station. The average gas tank in a vehicle holds between 13 and 16 gallons of fuel.
Gas tanks are also referred to by their capacity, so a mechanic might tell you that you have a 14-gallon gas tank.
Swimming Pool Capacities
Although gallons are a relatively small measurement, they’re still used to measure large amounts of liquid. How much a swimming pool holds is usually measured in gallons in the United States, and because gallons are larger than liters, you might also see gallons used to describe a pool’s capacity in other parts of the world.
The average home swimming pool holds between 18,000 and 20,000 gallons of water.
Soup
Milk and water aren’t the only food items that can be measured in gallons. Soup can also be measured by the gallon. A gallon is a large amount of soup, but a family might purchase or make a gallon of soup for dinner.
Foods for restaurants, such as soups, stews, and sauces, are also commonly measured in gallons because they are made in large quantities. This helps the chef figure out how much of a certain dish is being sold and how much should be made the next day.
Ziplock Bags and Storage Containers
Many Ziplock bags use liquid measurements to describe their capacity. Large bags, particularly freezer bags, often have a 1-gallon capacity.
Some plastic storage containers also use fluid measurements to give a more accurate idea of their capacity, and some large containers are designed to hold a gallon or more of liquid.
These containers and bags are a great way to store leftover soup or stock because they’re liquid-tight and can be frozen.
Paint
If you want to paint a room in your house, you’ll most likely need to purchase the paint in gallon increments. For small areas, you can buy a quart of paint instead.
However, a room of average size will require about 2 gallons of paint for complete coverage.
Shampoo, Conditioner, and Soap
If you have a favorite shampoo, hair conditioner, or soap, you might be able to purchase it by the gallon. These personal care items are often sold by the gallon so that salons or hotels can use them. You can also often purchase lotions by the gallon.
Glue
It might seem excessive to buy glue by the gallon, but school glue is often sold in large quantities because schools use so much. A teacher might purchase a gallon of glue. The gallon of glue can then be used to refill students’ individual glue bottles.
Aquariums and water conditioners
Home aquariums are generally sold by the gallon. A small aquarium would hold 10 gallons of water while larger aquariums hold 55 to 125 gallons of water.
If you have an aquarium, you’ve probably used a dechlorinating agent or a water conditioner. These liquid additives are usually sold in small quantities, but they can also be purchased by the gallon.
A gallon of water conditioner is a good option for aquarium enthusiasts with large tanks or for people who take care of aquariums for a living.
Other water additives, such as liquid chlorine or pool shock, are also often sold in gallon amounts. Liquid chlorine can be poured into your pool’s filtration system to get rid of algae and bacteria, keeping the pool clear. Shock acts similarly to chlorine, but it’s much stronger.
Coolers
Coolers are not liquid items, but the space inside them is often measured in gallons. A medium-sized cooler often has an internal capacity of about 6 gallons. Larger coolers might have an internal capacity of 10 to 15 gallons.
Automotive Fluids
Periodically, your vehicle will need to have fluids added to it to keep it running. This can include engine oil, antifreeze, and even windshield washer fluid. These liquids are often sold by the gallon. This is particularly true for antifreeze and windshield washer fluid. Engine oil, however, is more commonly sold by the quart.
Liquid Fertilizers and Pesticides
If you have a garden or keep indoor plants, you might need to purchase fertilizers to make sure the plants are receiving the nutrients they need. Fertilizers come in many forms, but liquid fertilizer is effective in that it can be applied directly to specific, targeted areas. Liquid fertilizers are often sold by the gallon.
Pesticides, particularly natural pesticides or any pesticides you spray on the plants, are also commonly sold by the gallon.
