What Size Thread Garden Hose: GHT Sizes & Adapter Guide

Most US garden hoses use 3/4-11.5 NH (GHT) straight threads with a washer seal.

If you have ever asked what size thread garden hose you own, you are not alone. I have set up yards, farms, and job sites for years, and I see the same confusion. This guide explains what size thread garden hose you likely have, how to confirm it fast, and how to pick the right fittings without leaks or returns.

The standard garden hose thread in the US

In the United States and Canada, the standard garden hose thread is called GHT or NH. The formal spec is 3/4-11.5 NH. It is a straight thread that seals with a rubber washer, not with tape.

Key points I check on every job:

• Thread type. 3/4-11.5 NH (also called GHT) per common plumbing standards.
• Seal method. A flat washer makes the seal. Not thread sealant.
• Male vs female. A hose bibb on the wall is male GHT. The hose end swivel is female GHT.
• Hose size vs thread size. A 5/8-inch hose is the inside diameter of the hose, not the thread.

When clients ask what size thread garden hose they need, I tell them to look for 3/4-inch GHT on the package. That is the common fit for almost all outdoor spigots, hose nozzles, Y-splitters, and sprinklers in the US.

GHT vs NPT: Why they do not mix

GHT (garden hose thread) has straight threads and needs a washer. NPT (National Pipe Taper) is tapered and seals on the threads. They look close, but they do not mate. Forcing them can ruin both parts.

What to remember:

• GHT spec. 3/4-11.5 NH, 60-degree straight threads, washer seal.
• NPT spec. 3/4-14 NPT, tapered threads, thread sealant or tape.
• Do not cross them. Use a proper GHT-to-NPT adapter if you must join them.

If you wonder what size thread garden hose will fit a pump or filter port marked 3/4 NPT, the answer is none without an adapter.

How to identify what size thread your garden hose has

Use this simple field test I use on service calls. It takes two minutes and avoids guesswork.

Steps:

• Look at the faucet. Most outdoor hose bibbs in the US are male 3/4 GHT. The face is flat for the washer.
• Check the hose end. The swivel nut on the hose takes a washer. That means GHT.
• Measure the outside diameter of the male threads. It should be about 1-1/16 inches for 3/4 GHT.
• Count threads. GHT has about 11.5 threads per inch. A thread gauge helps, but most folks skip this.
• Check the package. If you see 3/4 GHT or 3/4 NH, you are set.

Signs you need an adapter:

• The part says BSP, NPT, PF, or R on the box. That is not GHT.
• You feel the threads bind at the first turn. Stop. That is cross-threading.

If you still wonder what size thread garden hose you have, take the hose end to a hardware store. Ask them to test-fit a 3/4 GHT cap. It should spin on by hand and seat on the washer.

Is a 5/8-inch hose the same as a 3/4-inch thread?

No. 5/8 inch is the inside diameter of the hose. The threads are still 3/4 GHT in most US hoses.

What size is my outdoor spigot thread?

Almost always 3/4 GHT in the US and Canada. A few older or specialty valves can differ, but that is rare.

Do I need Teflon tape on garden hose threads?

No. GHT uses a flat washer to seal. Use new washers, not tape.

What size thread garden hose questions often start here. Follow these steps and you will know your match fast.

International thread standards and travel adapters

Outside North America, many fittings use BSP threads. The most common for garden gear is 3/4 BSP. It is straight like GHT but uses a 55-degree profile. It is not the same as GHT.

Regional norms I see:

• United Kingdom and EU. 3/4 BSP for hose connectors and mixers. Brands like push-fit systems often sit on BSP adapters.
• Australia and New Zealand. BSP is common for taps and garden fittings.
• North America. 3/4 GHT on hose bibbs and hoses.

If you move or buy gear from abroad, you may need a GHT-to-BSP adapter. When people ask what size thread garden hose adapter to buy for a UK sprayer in the US, the answer is GHT female to 3/4 BSP male.

Common fittings, adapters, and use cases

I carry a small kit in my truck. It solves 90% of hose thread mix-ups on site.

Go-to parts:

• GHT caps and plugs. For quick leak tests and winterization.
• GHT-to-NPT adapters. For filters, pumps, and drip systems with pipe threads.
• GHT-to-BSP adapters. For imported sprinklers or connectors.
• Quick-connect sets. Snap fittings save time and protect threads.
• Y-splitters and 90-degree elbows. Reduce stress on hose bibbs.

In my work, what size thread garden hose comes up when we add a filter with 3/4 NPT ports. I install a GHT female to 3/4 NPT male adapter and it works clean.

Troubleshooting leaks and cross-threading

Most leaks come from worn or missing washers. Cross-threading is next. Both are easy to fix.

Do this first:

• Replace the washer. Use a fresh, soft washer in the hose swivel.
• Hand-tighten only. A snug hand turn is enough. Over-tightening ruins washers.
• Check alignment. If it does not spin on by hand, back off and re-align.
• Avoid tape on GHT. Tape does not help a flat washer joint.

If you still have a drip at the faucet face, the spigot seat may be scarred. A brass washer or a conical seat washer can help. When folks ask what size thread garden hose washer to buy, get a standard garden hose washer set. It fits 3/4 GHT.

Buying guide and checklist

Here is the checklist I give new homeowners. It saves returns and wasted trips.

Look for these labels:

• 3/4-inch GHT or 3/4 NH on any hose, nozzle, or splitter.
• Washer included or extra washers. Keep spares on hand.
• Material quality. Brass for durability, polymer for light use.
• Flow needs. 5/8-inch hose for most yards, 3/4-inch hose for high flow.

Ask yourself what size thread garden hose adapters you need before you buy. If a device lists NPT or BSP, add the right adapter to your cart.

Safety, flow, and performance notes

Thread size affects fit, not flow. Flow depends on hose inside diameter, length, and pressure. A 3/4-inch hose flows more than a 5/8-inch hose at the same pressure, but it is heavier.

Rules of thumb I use:

• Keep hoses as short as possible for high-flow jobs.
• Use 3/4-inch hose for filling pools or feeding pressure washers.
• Replace worn washers each season to protect threads and seals.

When you ask what size thread garden hose matters for pressure, the real key is hose diameter and run length, not the GHT thread itself.

Frequently Asked Questions of what size thread garden hose

What size thread garden hose is standard in the US?

The standard is 3/4-11.5 NH, also called GHT. It is a straight thread that seals with a flat washer.

How do I know what size thread garden hose I have at home?

Check the spigot and hose end for a flat washer seat and a 3/4 GHT mark. Most US homes use this size on all outdoor taps.

Can I connect a garden hose to 3/4 NPT threads?

Not directly. You need a GHT-to-NPT adapter because NPT is tapered and GHT is straight.

Do quick-connects change what size thread garden hose I need?

No. Good quick-connects are made with GHT ends. They just make it easier to attach and remove tools.

What size thread garden hose is used on washing machine hookups?

Washing machine hoses in North America also use 3/4 GHT. Always use new rubber washers for a good seal.

Is 1/2-inch garden hose thread a thing?

Not in common US outdoor use. 1/2 inch usually refers to hose diameter, while the thread remains 3/4 GHT.

Will BSP hose fittings work with my US hose?

Not without an adapter. BSP and GHT are different thread forms and will not seal right together.

Conclusion

Most homeowners only need one answer: your hose and spigot use 3/4 GHT with a washer. Know that, keep spare washers, and use the right adapters for NPT or BSP gear. Your gear will last longer and you will stop chasing leaks.

Put this guide to work today. Check your hose ends, buy the correct adapters, and label your parts bin. If this helped you understand what size thread garden hose you have, share it with a neighbor, subscribe for more simple fixes, or drop your question in the comments.