Garden Hose Sizes: Diameter, Length, Threads and Flow
Inside and outside diameters, standard lengths, thread sizes and how much pressure each hose size loses over distance, so you can pick a hose that reaches, fits the spigot and still delivers water at the end.
The standard garden hose has a 5/8 in (15.9 mm) inside diameter; 1/2 in (12.7 mm) and 3/4 in (19.1 mm) hoses are the other common sizes. Hoses are sold in 25, 50, 75 and 100 ft lengths (7.6 to 30.5 m), and in the US every one uses 3/4 in garden hose thread (GHT), 11.5 threads per inch, with a male thread about 1 1/16 in (27 mm) across.
- Standard diameter
- 5/8 in (15.9 mm)
- Common length
- 50 ft (15.2 m)
- US fitting
- 3/4 in GHT, 11.5 TPI
- Thread diameter
- 1.0625 in (27 mm)
On this page
Garden hose diameters
A hose's size is its inside diameter (ID), the bore the water flows through. The outside diameter (OD) depends on the wall thickness, which varies by brand and material, so it is shown as a range.
| Hose size | Inside (mm) | Typical outside | Water in 50 ft | Best for |
|---|---|---|---|---|
| 1/2 in | 12.7 mm sold as 12.5-13 mm | 0.75-0.8 in 19-21 mm | 0.51 gal 1.9 L | Short runs, pots, light hand watering |
| 5/8 in | 15.9 mm sold as 15-16 mm | 0.88-1.06 in 22-27 mm | 0.80 gal 3.0 L | General watering, washing, most sprinklers |
| 3/4 in | 19.1 mm sold as 19 mm | 1-1.25 in 25-32 mm | 1.15 gal 4.3 L | Long runs, high-flow sprinklers, filling pools |
| 1 in | 25.4 mm | 1.25-1.5 in 32-38 mm | 2.04 gal 7.7 L | Farm and commercial use |
Even a small step in diameter makes a big difference to flow, because the bore's area grows with the square of the diameter. A 5/8 in hose has 56% more bore area than a 1/2 in hose, and a 3/4 in hose 44% more than a 5/8 in.
How to tell what size your hose is
- Read the print: most hoses have the size and length printed along the jacket or on the coupling.
- Measure the bore: look into the cut end of the hose (not the coupling, which is narrower) and measure across the inside with calipers or a ruler. About 1/2, 5/8 or 3/4 in.
- Don't go by the coupling: 1/2, 5/8 and 3/4 in hoses all use the same 3/4 in thread in the US.
Garden hose lengths
| Length | Metric | Typical use |
|---|---|---|
| 10-15 ft | 3-4.6 m | Leader hose from spigot to reel; RV and boat |
| 25 ft | 7.6 m | Balconies, patios, small front yards |
| 50 ft | 15.2 m | Most suburban yards; the most common length |
| 75 ft | 22.9 m | Larger lots, reaching the back fence |
| 100 ft | 30.5 m | Large properties; use 5/8 or 3/4 in |
Metric markets sell 10, 15, 20, 25, 30 and 50 m hoses. To choose a length, walk the path the hose will follow around beds, corners and the house (not a straight line), from the spigot to the farthest point you water, and add about 10%. A hose that is much too long is heavier to drag, slower to coil and loses more pressure.
Hose threads and fittings
In the US and Canada, garden hoses, spigots, nozzles and sprinklers use garden hose thread (GHT), defined in ASME B1.20.7 as 3/4-11.5 NH. It has a straight (parallel) thread and seals on a flat rubber washer inside the female coupling. The UK, Europe and Australia use BSP threads on taps, and most hoses connect through push-fit click connectors instead of threads.
| Thread | Where used | Threads per inch | Male thread diameter | Seals on |
|---|---|---|---|---|
| 3/4 in GHT | US garden hoses, spigots, washing machine hoses | 11.5 | 1.0625 in 26.99 mm | Rubber washer |
| 3/4 in NPT | US pipe and plumbing fittings | 14 | 1.050 in 26.67 mm | Tapered threads plus sealant |
| 1/2 in NPT | US pipe; some spigot inlets | 14 | 0.840 in 21.34 mm | Tapered threads plus sealant |
| 3/4 in BSP | UK, EU and Australian outdoor taps | 14 | 26.44 mm 1.041 in | Washer or O-ring |
| 1/2 in BSP | UK and EU taps | 14 | 20.96 mm 0.825 in | Washer or O-ring |
3/4 in GHT, 3/4 in NPT and 3/4 in BSP are all about 1 in across, and a GHT fitting can be started on the other two. The thread pitch differs (11.5 vs 14 per inch), so it binds after a turn or two and leaks. Use a proper adapter, for example GHT female to NPT male, rather than forcing it.
- Hose washers: a flat rubber washer about 1 in across fits every GHT female coupling. Most leaks at the spigot are a missing or flattened washer.
- Quick connectors: brass or plastic quick-connect sets screw onto the GHT ends; the click-fit halves are brand-specific in some systems, so buy matching pairs.
- Pressure: household water is usually 40 to 80 psi (2.8 to 5.5 bar). The International Plumbing Code requires a pressure-reducing valve where static pressure exceeds 80 psi. Hoses rated for a burst pressure of several hundred psi have ample margin.
Pressure loss by hose size and length
Friction inside the hose eats pressure as water flows. The smaller the bore and the longer the hose, the less pressure is left for the nozzle or sprinkler. The table is calculated with the Hazen-Williams equation for a smooth bore (C = 140); couplings and kinks add more loss.
| Flow | 1/2 in hose | 5/8 in hose | 3/4 in hose |
|---|---|---|---|
| 5 gal/min 19 L/min | 14 psi | 5 psi | 2 psi |
| 8 gal/min 30 L/min | 33 psi | 11 psi | 5 psi |
| 10 gal/min 38 L/min | 50 psi | 17 psi | 7 psi |
Double the figures for 100 ft. At 8 gpm, a 100 ft, 1/2 in hose loses about 66 psi, more than many homes supply, so the water barely trickles out. The same run in 5/8 in loses about 22 psi and in 3/4 in about 9 psi.
- Measure your flow. Time how long the open spigot takes to fill a 5 gal (19 L) bucket. 40 seconds means 7.5 gpm.
- Check what the end device needs. Sprinklers and pressure washers list a minimum flow (gpm) and pressure (psi) on the box.
- Pick the diameter. Find the hose size whose loss over your length still leaves that pressure. For hand watering, any size works; for sprinklers over 50 ft, use 5/8 in or larger.
Expandable, soaker and drip hoses
- Expandable hoses are sold by their stretched length under pressure. Empty, they shrink to roughly a third to a half of that, so a "50 ft" expandable hose may be 17 to 25 ft long until the water is on. Their inner tube is narrow, so they deliver less flow than a 5/8 in hose of the same length.
- Soaker hoses are usually 1/2 or 5/8 in and 25 to 100 ft long. They work best on runs under about 100 ft at low pressure (a pressure regulator of around 10 to 25 psi helps keep the flow even).
- Drip tubing sold as "1/2 in" is not one size: different brands make it with outside diameters of about 0.600 to 0.710 in. Fittings must match the tubing's exact size, so check the ID × OD printed on it. Micro tubing for individual emitters is 1/4 in (about 6 mm) outside.
Hose reel and storage sizes
Hose reels are rated for a length of 5/8 in hose. The space on the drum depends on the hose's outside diameter, so a thicker hose fits less:
- 3/4 in hose takes roughly 40 to 50% more space per foot than 5/8 in, so a reel rated for 150 ft of 5/8 in holds about 100 ft of 3/4 in.
- 1/2 in hose takes about two-thirds of the space, so the same reel takes around 200 ft or more.
- Wall hangers for a 50 ft, 5/8 in hose are usually 10 to 12 in across; a 100 ft hose needs a deep hanger or a reel.
Coiled, a 50 ft, 5/8 in hose makes a loop about 18 to 24 in (46 to 61 cm) across and 6 to 8 in (15 to 20 cm) thick.
For watering containers and beds, see the planter size guide and the flower pot size chart. Topping up a pool from a hose takes a while: at 8 gpm, a 19,000 gallon pool from the pool size guide needs about 40 hours. Spigots connect to household plumbing sized in the pipe size chart.
Frequently asked questions
What size is a standard garden hose in mm?
A standard 5/8 in garden hose is 15.9 mm across inside, often sold as 15 or 16 mm. The outside diameter is usually about 22 to 27 mm, depending on the wall thickness. In the UK and Europe, the equivalent hose is sold as 15 mm.
What is the outer diameter of a garden hose?
It varies with material and wall thickness. Typical figures: 1/2 in hoses about 3/4 in (19 to 21 mm) outside, 5/8 in hoses about 7/8 to 1 1/16 in (22 to 27 mm), and 3/4 in hoses about 1 to 1 1/4 in (25 to 32 mm). Measure your own hose if you are buying clamps or reel guides.
How long is an average garden hose in inches?
The most common length, 50 ft, is 600 in (15.24 m). A 25 ft hose is 300 in, 75 ft is 900 in and 100 ft is 1,200 in. Hoses are measured from coupling to coupling.
Are garden hose threads the same as pipe threads?
No. Garden hose thread (GHT) is 3/4 in with 11.5 threads per inch and seals on a rubber washer. 3/4 in NPT pipe thread has 14 threads per inch and is tapered, so it seals on the threads. They can look alike but will not seal; use a GHT to NPT adapter.
What is a 1 1/2 inch hose used for?
A 1 1/2 in hose is not a garden hose. It is a lay-flat discharge hose for sump and trash pumps, or a fire hose, and uses camlock or fire-hose (NH) couplings rather than garden hose threads.
What size hose for a 100 ft run?
Use 5/8 in for normal watering and 3/4 in if you run a sprinkler or pressure washer at the far end. At 8 gallons per minute, a 1/2 in hose loses about 66 psi over 100 ft, more than most homes have, while 5/8 in loses about 22 psi and 3/4 in about 9 psi.