What Thread Size Is A Garden Hose: GHT Vs NPT Explained

In the US, garden hoses use 3/4-11.5 NH (GHT) straight threads with washers.

If you have ever stood at a faucet holding two parts that almost fit, this guide is for you. I work with hoses and fittings in real yards, on job sites, and with clients who ask what thread size is a garden hose. I will explain how the standard works, how to measure it, and how to avoid leaks and frustration. By the end, you will know exactly what thread size is a garden hose and how to use it with confidence.

What thread size means and why it matters

Thread size describes how two ends join and seal. It covers the major diameter, thread pitch, and thread shape. On a garden hose, the thread is straight. The seal comes from a flat washer, not from the threads.

In North America, the standard is 3/4-11.5 NH, also called GHT. That means about 3/4 inch outside diameter and 11.5 threads per inch. NH is a straight thread, so it does not wedge like pipe threads.

Knowing what thread size is a garden hose helps you pick the right adapters, splitters, and quick connectors. It also stops cross-threading and drips at the spigot. Once you get it right, the setup is fast, clean, and repeatable.

Standard garden hose thread sizes by region

Most US and Canadian outdoor faucets and hoses use 3/4-11.5 NH (GHT). The faucet or hose bib usually has male hose thread (MHT). The hose end that screws on is female hose thread (FHT). The seal is a flat rubber washer.

Outside North America, many taps use BSP threads. Common sizes are 1/2 BSP and 3/4 BSP. BSP uses a different angle and 14 threads per inch at 3/4 size. It will not seal with GHT without an adapter.

Quick guide:

United States and Canada: 3/4-11.5 NH/GHT straight thread with a flat washer
United Kingdom and most of Europe: 3/4 BSPP or 1/2 BSPP parallel thread, often used with quick-connect sets
Australia and New Zealand: Mostly BSP parallel thread on outdoor taps
Washers and quick connectors: Region-specific, but adapters exist to bridge GHT and BSP

If you import a nozzle or splitter, check if it is GHT or BSP. Mixing types explains many “it almost fits” headaches. When someone asks what thread size is a garden hose, the right answer depends on where you live and the gear you buy.

How to check what thread size is a garden hose at home

You can confirm your thread in minutes with simple tools. Here is my field method that saves trips back to the store.

Read the stamp or tag. Many brass fittings are marked with NH, GHT, NPT, or BSP.
Measure the outside of the male thread. A ruler works. GHT will be near 1.06 inches across.
Count threads per inch. Mark one inch with tape and count crests. GHT has 11 or 12 per inch; the standard is 11.5.
Look at the form. GHT is straight. If the threads look tapered, you may have NPT pipe thread.
Check for a washer. GHT seals with a flat washer. NPT needs thread tape or sealant.
Test fit with a known part. Take a hose nozzle you trust and see if it starts by hand.

If you still wonder what thread size is a garden hose, take the fitting to a plumbing desk. They can match it with a thread gauge in seconds. I have done this many times for clients, and it always removes doubt.

Hose diameter vs thread size

Hose inner diameter is not the same as thread size. Most home hoses are 5/8 inch ID. Some are 1/2 inch for light use, and 3/4 inch for high flow. All of these common hoses still use 3/4-11.5 GHT ends in the US.

This is where people get stuck. They buy a 5/8 inch fitting when they meant 3/4 GHT. Remember, what thread size is a garden hose refers to the connection, not the water passage inside the hose.

I once helped a neighbor who bought a 5/8 inch metal connector online. It would not start on the spigot. The piece was 5/8 NPT pipe thread, not 3/4 GHT. A simple FHT x NPT adapter fixed it.

Adapters, fittings, and making parts play nice

If you need to bridge systems, use the right adapter. A small brass adapter can save a whole setup. Here are common ones I use on installs.

FHT to NPT adapters. Join a garden hose to pipe-threaded pumps, filters, or PVC.
BSP to GHT adapters. Connect EU quick connectors to US spigots or the other way around.
Y splitters with GHT. Turn one faucet into two zones without tools.
Vacuum breaker and backflow devices. Many screw right onto MHT on the spigot.
Quick-connect sets. Choose brass for long life. They come in FHT and MHT options.

Do not wrap PTFE tape on GHT threads. The seal is the washer. Use tape only on tapered pipe threads like NPT. If you keep asking what thread size is a garden hose while hunting for tape, the answer is still GHT with a flat washer.

Common problems and easy fixes

Even the right thread can leak or bind. Here are the issues I see most, plus fast fixes you can try today.

Drips at the faucet. Replace the flat washer. Make sure it sits flat and is not cracked.
Cross-threading. Start by hand for a full turn. If it feels gritty, back off and realign.
Stuck couplings. Use two wrenches. Hold the faucet body to avoid stress. A drop of silicone spray helps next time.
White tape on hose threads. Remove it. Install a new washer instead.
Corrosion on aluminum hose ends. Switch to brass ends. Use a dielectric washer if mating to brass.

Keep a small kit with spare washers, a washer puller, and one FHT x NPT adapter. It solves most issues on the spot. When someone asks what thread size is a garden hose because of a leak, the real fix is often a fresh washer.

Buying guide and pro tips

Choose fittings that hold up and fit right the first time. Here is how I spec parts for clients and my own yard.

Solid brass couplings. They resist crush and last longer than thin stamped ends.
Thick flat washers. Keep spares. Look for soft rubber or EPDM for outdoor use.
Large grip collars. Easier to tighten by hand, even with wet fingers.
True GHT labeling. Look for 3/4 GHT, FHT, or MHT on the package.
Quick connects that match your thread. Brass sets seal better and do not pop off under surge.
Short leader hoses. Save wear on the spigot and reduce stress on the joint.

If you forget what thread size is a garden hose while shopping, snap a photo of your faucet and hose end. Store staff can match it to the right FHT or MHT part in seconds.

Frequently Asked Questions of what thread size is a garden hose

Is garden hose thread the same as pipe thread?

No. Garden hose thread is straight and seals with a flat washer. Pipe thread is tapered and seals with tape or paste.

What is the exact US garden hose thread spec?

It is 3/4-11.5 NH, often called GHT. The ends are named FHT for female hose thread and MHT for male hose thread.

Can I connect a BSP tap to a US garden hose?

Yes, with a BSP to GHT adapter. Without the adapter, the threads may start but will not seal.

Do 1/2 inch hoses use smaller threads?

In the US, no. Most 1/2 inch, 5/8 inch, and 3/4 inch hoses all use 3/4 GHT ends.

Should I use thread tape on a garden hose?

No. Replace the flat washer instead. Use thread tape only on tapered pipe threads like NPT.

How do I measure my hose thread at home?

Use a ruler to check the diameter and count threads per inch. Look for a flat washer to confirm it is GHT.

Why does my new nozzle still leak?

Check the washer in the hose female end. If it is missing, worn, or hard, replace it and hand-tighten.

Conclusion

Most North American hoses and spigots use 3/4-11.5 GHT straight threads with a flat washer. If a part will not seal, check the washer, confirm the thread, and use the right adapter for NPT or BSP. Understanding what thread size is a garden hose saves time, money, and water.

Take ten minutes today to check your fittings and stock spare washers. You will fix small leaks fast and avoid bigger repairs. Want more hands-on tips like this? Subscribe, ask a question, or share your own hose setup and I will help you dial it in.