A standard 5/8-inch, 100-foot garden hose holds about 1.6 gallons of water when it is completely full.
A 100-foot garden hose does not hold one fixed amount of water. The answer changes with the hose’s inside diameter. That detail matters more than most people think, because a skinny hose and a wide hose can differ by more than a gallon over the same length.
If you just want the plain answer, most residential 100-foot hoses are 5/8 inch wide inside, and that size holds about 1.59 gallons of water. A 1/2-inch hose holds about 1.02 gallons. A 3/4-inch hose jumps to about 2.29 gallons. So when someone asks how much water is in a 100 foot garden hose, the real answer is, “Which hose size?”
That number is handy for more than trivia. It tells you how much water sits in the hose before the fresh cold water reaches your nozzle, how much weight you are dragging across the yard, and how much water drains out when you coil the hose and store it.
Why The Hose Diameter Changes The Answer
Garden hose capacity is a volume question. Length matters, but the inside width matters just as much. Water fills the whole inside of the hose, so a wider hose stores more water all the way down its length.
Think of it like two hallways that are the same length. The wider one holds more stuff. A hose works the same way. Double the inside width and the water capacity does not just double. It climbs much faster because the extra width adds area across the full length of the hose.
That is why a 1-inch hose can hold about four times as much water as a 1/2-inch hose over the same 100 feet. Same distance. Big jump in capacity.
How Much Water Is In A 100 Foot Garden Hose? The Math By Diameter
The math comes from the volume of a cylinder: radius squared, times pi, times length. For a 100-foot hose, the length is 1,200 inches. Once you get cubic inches, you can convert that to gallons. The NIST gallon definition uses 231 cubic inches per U.S. gallon.
Manufacturers and retailers list hose sizes by inside diameter, which is the number you want for water capacity. A hose sold as 5/8 inch is measured by that inside opening, not by the outside rubber wall. A product spec sheet such as Flexzilla’s garden hose specs shows 100-foot hoses sold in 5/8-inch and 3/4-inch sizes, while Gilmour’s hose listings show 1/2-inch, 5/8-inch, 3/4-inch, and 1-inch options.
Using that standard cylinder formula, here are the water amounts for a 100-foot hose at several inside diameters.
Capacity Table For A 100-Foot Hose
| Inside Diameter | Water Held In 100 Feet | Metric Equivalent |
|---|---|---|
| 1/4 inch | 0.25 gallons | 0.97 liters |
| 3/8 inch | 0.57 gallons | 2.17 liters |
| 1/2 inch | 1.02 gallons | 3.86 liters |
| 5/8 inch | 1.59 gallons | 6.03 liters |
| 3/4 inch | 2.29 gallons | 8.69 liters |
| 7/8 inch | 3.12 gallons | 11.81 liters |
| 1 inch | 4.08 gallons | 15.44 liters |
The 5/8-inch row is the one most homeowners care about. It is the size you will see again and again in stores because it balances flow, weight, and handling well for day-to-day yard work. If your hose label says 5/8 inch and 100 feet, you are looking at about 1.6 gallons when the hose is fully charged with water.
That means the hose is carrying a little over 13 pounds of water before you count the hose material itself. A wider 3/4-inch hose carries closer to 19 pounds of water. Once you add the rubber or polymer shell, the full hose feels a lot heavier than it looks hanging on the wall.
What Those Gallons Mean In Real Yard Use
Capacity changes how the hose feels and how it behaves. A larger hose has more water waiting inside it, which can be handy for higher-flow jobs like soaking beds, washing a driveway, or feeding a sprinkler at the far end of a long run. But it is also heavier, slower to empty, and a bit more awkward to coil.
A smaller hose is lighter and easier to move. That makes it pleasant for hand watering, patios, and smaller gardens. The trade-off is lower water volume inside the line, which can mean a weaker stream at the nozzle once distance and pressure loss start stacking up.
This is why two 100-foot hoses can feel so different in your hands. The length is the same. The inside width changes the whole experience.
How Long It Takes Fresh Water To Reach The End
When you turn on a hose, the first water out is the water that has been sitting in the line. On a warm day, that can be hot. On a cool morning, it can be cold. If your 100-foot hose holds 1.6 gallons and your nozzle is running at 4 gallons per minute, you need around 24 seconds to push all the old water out.
A 3/4-inch hose with 2.29 gallons inside takes closer to 34 seconds at that same flow. That does not sound like much, but it is enough to notice when you are waiting for cooler water to rinse a pet, fill a can, or water delicate plants.
Common 100-Foot Hose Sizes And What To Expect
Most people shopping for a 100-foot hose land on one of three sizes: 1/2 inch, 5/8 inch, or 3/4 inch. Each one has its own sweet spot.
- 1/2 inch: Lighter, easier to drag, good for lighter watering tasks.
- 5/8 inch: The usual pick for general home use. Good flow without getting too bulky.
- 3/4 inch: Better for long runs, bigger yards, and jobs where you want more volume at the end of the line.
If you do not know your hose size, check the printing on the jacket or the product label near the fittings. The diameter is often part of the model description, right next to the length.
Practical Comparison Of Popular Hose Sizes
| Hose Size | Full Water Capacity | What It Feels Like In Use |
|---|---|---|
| 1/2 inch × 100 ft | About 1.02 gallons | Lighter to pull, fine for lighter hand watering |
| 5/8 inch × 100 ft | About 1.59 gallons | Good middle ground for most home yards |
| 3/4 inch × 100 ft | About 2.29 gallons | Heavier, with stronger volume for long runs |
Why Your Hose May Not Drain The Full Amount
The figures above assume the hose is filled end to end. In real use, the amount left inside can be lower if the hose is kinked, partly drained, stretched uphill, or still under pressure with a shut-off nozzle attached. A coiled hose on a reel can hold little pockets of water even after you think it is empty.
That is one reason a “stored” hose can still spill more water than you expect when you disconnect it. The full-capacity number tells you the upper limit. Your actual leftover amount depends on how the hose sits, how long you let it drain, and whether one end is raised.
Easy Rule Of Thumb If You Forget The Exact Number
If you need a fast estimate, use this:
- 1/2-inch hose: about 1 gallon per 100 feet
- 5/8-inch hose: about 1.6 gallons per 100 feet
- 3/4-inch hose: about 2.3 gallons per 100 feet
That rule of thumb is close enough for watering math, draining, storage, and weight planning. If you are buying a new hose and want the most familiar all-round size, 5/8 inch is usually the number you will run into.
Picking The Right Takeaway
So, how much water is in a 100 foot garden hose? For the hose size most homes use, the answer is about 1.6 gallons. If your hose is narrower, it holds less. If it is wider, it holds more. That one measurement changes the whole total.
Once you know the diameter, the guesswork is gone. You can tell how much water is sitting in the line, how heavy the hose will feel when full, and how long it may take for fresh water to reach the nozzle. For a small detail printed on the side of a hose, diameter does a lot of work.
References & Sources
- National Institute of Standards and Technology (NIST).“NIST HB 44 2024 Appendix C: General Tables of Units of Measurement.”States that one U.S. gallon equals 231 cubic inches, which supports the hose-capacity calculations.
- Flexzilla.“Garden Hose Specs.”Lists 100-foot garden hoses in standard inside diameters such as 5/8 inch and 3/4 inch, supporting the size references used in the article.
- Gilmour.“Flexogen Heavy Duty Hose.”Shows that 100-foot hoses are sold in 1/2-inch, 5/8-inch, 3/4-inch, and 1-inch sizes, supporting the capacity comparison table.