How many regular water bottles does it take to make a gallon?

Water is an essential part of our daily lives. We need it to stay hydrated, for cooking, cleaning, and many other uses. A gallon of water contains 128 fluid ounces. Knowing how many regular water bottles it takes to equal a gallon can be useful for planning purposes – for example, when stocking up on bottled water for an emergency or calculating how much water you need for a camping trip.

Quick Answer

It takes approximately 15 regular water bottles to make a gallon, assuming that a “regular” bottle contains 16.9 ounces of water.

Regular Water Bottle Sizes

When referring to a “regular” water bottle, most people think of the common 16.9 ounce plastic bottles that are widely available in grocery stores, convenience stores, vending machines, etc. However, water bottle sizes can vary.

Here are some of the most common sizes for single-serve water bottles:

  • 12 ounces
  • 16.9 ounces (half liter)
  • 20 ounces
  • 24 ounces
  • 32 ounces

For the purposes of this article, we will assume “regular” means 16.9 ounces, since that is the most standard size.

How Many Ounces in a Gallon?

Before we calculate how many bottles it takes, let’s review how many ounces are in a gallon:

  • 1 gallon = 128 fluid ounces

Knowing this conversion between gallons and ounces will make the math easier.

Calculating Bottles for a Gallon

Now we can calculate how many 16.9 ounce water bottles are needed to make a gallon:

  • 128 oz (gallon) / 16.9 oz (regular bottle) = 7.57 bottles

So mathematically, it takes approximately 7.57 bottles. However, since we need whole bottles, we round up to 8 regular water bottles.

To make the math simpler, we can also break a gallon down into groups of water bottles:

  • 128 oz / 16.9 oz = 7 full bottles
  • With 7 bottles = 7 x 16.9 oz = 117.3 oz
  • Leaves 10.7 oz remaining
  • Since a regular bottle is 16.9 oz, we need 8 bottles total

As shown above, if you take 7 full 16.9 oz water bottles, that leaves you with 10.7 oz still needed to reach a gallon. Thus, you need 1 more regular bottle, for a total of 8 bottles.

Visual Representation

Number of Bottles Total Ounces
7 bottles 117.3 oz
+ 1 bottle + 16.9 oz
= 8 bottles = 128 oz (1 gallon)

This table provides a visual summary of how 7 full bottles leaves you short of a gallon, but 8 regular water bottles gives you 128 ounces for the full gallon.

Variation With Different Sized Bottles

The number of bottles needed to make a gallon changes if you use smaller or larger bottles:

Bottle Size Bottles for Gallon
12 oz 10-11 bottles
16.9 oz (regular) 8 bottles
20 oz 6-7 bottles
24 oz 5-6 bottles
32 oz 4 bottles

This table shows how many bottles you need for a gallon based on different sized bottles. The range accounts for rounding up to the nearest full bottle.

Gallon Equivalents of Common Bottle Sizes

Here is how many of other common bottle sizes make up a gallon:

  • 12 oz bottles: A gallon is equal to 10-11 of the 12 oz bottles
  • 20 oz bottles: A gallon equals 6-7 of the 20 oz bottles
  • 24 oz bottles: A gallon is equal to 5-6 of the 24 oz size
  • 32 oz bottles: A gallon equals 4 of the 32 oz size

So if you had a scenario where you only had one of the above bottle sizes on hand, these equivalents give you an idea of how many you would need to meet a gallon.

Factors That Change Bottle Volume

It’s important to keep in mind that the actual volume of water in a bottle may vary slightly from the labeled size, due to these factors:

  • Plastic bottle manufacturing processes result in a small range of variance from the stated volume.
  • Bottles can be overfilled or underfilled during production.
  • Temperature can cause small changes in volume.
  • Opening and resealing bottles allows a small amount of air to enter, taking up space.

These minor variances mean a 16.9 oz bottle may not always contain exactly 16.9 oz. The differences are usually negligible. But technically the bottle volumes are not exactly precise.

Tips for Accurately Measuring Water

For situations where it’s important to precisely measure gallons of water, use these tips:

  • Use a measuring cup or pitcher that measures exact fluid ounces.
  • Weigh water on a food scale – 16.9 oz equals 1.06 pounds.
  • For larger quantities, use gallon size containers with volume markings.
  • Practice measuring with bottles/containers before relying on them for critical uses.
  • Factor in extra bottles to account for any discrepancies in true volumes.

Following these tips helps ensure accuracy when it matters most.

Alternative Methods to Get a Gallon of Water

While this article focuses on water bottles, there are other ways to get a gallon of water if bottles are not convenient or available:

  • Tap water: Let your faucet run until 1 gallon is reached on your water meter.
  • Large jugs: Purchase a plastic jug, such as those found on water coolers, that contains 1 gallon.
  • Reusing milk/juice jugs: Thoroughly clean and sanitize 1-gallon plastic containers and fill with tap water.
  • Reusing soda syrup containers: Some restaurants will give out empty, sanitized 1-gallon syrup jugs that can hold water.

With some creativity and planning, you may be able to get the equivalent of a gallon of water without needing to purchase cases of individual water bottles.

Best Practices When Reusing Containers for Water

If reusing milk jugs, soda syrup containers, or other items to hold drinking water, follow these guidelines:

  • Choose food-grade HDPE #2 plastics only.
  • Thoroughly wash with hot, soapy water.
  • Sanitize by rinsing with a dilute bleach solution.
  • Check for cracks or damage affecting integrity.
  • Consider replacing old caps/lids with new ones.
  • Label container as “drinking water” to avoid confusion.
  • Use proper storage conditions to avoid bacterial growth.

Taking these precautions helps prevent health issues from reused containers when filling them with water.

Water Handling Safety

When handling and storing water in bulk quantities, keep these safety tips in mind:

  • Lifting heavy bottles/jugs can cause back strains and injuries. Use proper lifting techniques or get help moving them.
  • Transport large amounts of water securely by vehicle to prevent shifting and spillage.
  • Store water in cool, dry areas away from chemicals and other contaminants.
  • Check containers for damage after transport that could lead to leakage.
  • Keep water in sealed containers to prevent accidental ingestion of chemicals or contaminated water.

Being mindful of these safety tips when moving and storing gallons of water helps avoid accidental leakage, contamination, or injuries.

Uses for Measuring Gallons of Water

Some examples where knowing how to measure gallons using water bottles could come in handy include:

  • Assembling emergency water supplies for natural disasters.
  • Planning enough drinking water for camping trips and hikes.
  • Keeping enough water on hand for large events or gatherings.
  • Making large batches of beverages for parties or sporting events.
  • Filling large decorative water features and fountains.
  • Caring for livestock and farm animals during periods of drought.

For these types of situations where having access to gallons of water is important, this guide on bottle equivalents can assist with planning and preparation.

Cost of Bottled Water Gallons

If purchasing cases of bottled water to obtain gallons, the typical cost is:

  • 24-pack of 16.9oz bottles = $4-$8
  • Gallons needed: 8 bottles x 3 packs = 24 bottles
  • So 1 gallon costs $12-$24 using 16.9oz bottled water

Buying larger bottles such as 24oz or 32oz sizes can lower the cost per gallon somewhat. And purchasing store brands instead of national brands can also save money. But bottled water gallons ultimately cost much more than a gallon of tap water.

Environmental Impact of Bottled Water

Drinking water from the tap is not just cheaper, but also more eco-friendly than bottled water. Consider these environmental impacts:

  • U.S. landfills received over 50 billion plastic water bottles in 2021. Few get recycled.
  • It takes 3 times the water to produce bottled water than what ends up inside the bottle.
  • Plastic bottle production uses fossil fuels for materials and factory power needs.
  • Transporting bottled water long distances has a large carbon footprint.

Tapping into readily available municipal water supplies eliminates these negative environmental effects and plastic waste issues posed by bottled water whenever possible.

Comparison of Bottled Water vs Tap Water

Bottled Water Tap Water
Convenience Highly convenient personalized bottles on-the-go Less convenient, requires reusable bottle or cup
Portability Very portable and easy to carry Not portable for drinking away from home faucet
Cost Expensive per gallon Essentially free from home faucet
Safety Generally safe if unopened Safe in most U.S. municipalities
Environmental impact Negative – plastic waste and pollution Much lower impact
Taste Varies by brand and source Can vary by municipal source

This comparison table summarizes some of the key differences between bottled water and tap water as common sources of drinking water.

Frequently Asked Questions

Does bottled water go bad or expire?

Bottled water does not truly expire, but its quality degrades over time. Under proper storage conditions, bottled water can stay fresh tasting for around 2 years past its printed expiration date. Keeping water sealed and away from sunlight and chemicals extends its shelf life.

Does water bottle size include the cap?

No, the stated volume on a plastic water bottle label reflects just the contents, not including the cap. The cap displaces a tiny amount of internal volume. So a 16.9 oz bottle contains 16.9 oz of water, not counting a negligible amount displaced by the cap.

Can you reuse plastic water bottles?

It’s best not to reuse disposable plastic water bottles. Reusing and washing them can degrade the plastic and release chemicals into the contents over time. For reusable bottles, go with stainless steel, glass, or BPA-free bottles designed to be washed and refilled.

Are most plastic water bottles BPA free?

Yes, most are now BPA free. Since around 2014, many brands switched to polyethylene terephthalate (PET) plastic that does not contain bisphenol A (BPA), a chemical that can leach into contents when bottles heat up.

Why are some water bottles 16.9 ounces?

The 16.9 ounce size for plastic water bottles was chosen partly because that specific volume is equal to one-half liter. Since the metric system is widely used internationally, bottles sized at even liters or half-liters simplify production and distribution.


In summary, it takes about 8 regular 16.9 ounce water bottles to equal a gallon of water. This varies based on the exact bottle size, with smaller bottles requiring more to reach a gallon, and larger bottles needing fewer. With some basic math and common bottle sizes in mind, you can easily calculate how many bottles you need to prepare gallons of water for emergency preparedness, camping, events, or other situations where having access to clean water is important. Just be sure to store and handle the water properly for safety.

Leave a Comment