What Size is the O-Ring Fitted to a Garden Hose?

It’s a pain in the arse when water starts leaking around the connector on a garden hose. Usually the o’ring has disintegrated, or the hose connection has started coming adrift.

The physical hose connection is often quite easy… You can tighten it up.

But if the o-ring has broken, or become perished. You will need to get a new one.

But, what size is the o-ring..?

What Size is the O-Ring Fitted to a Garden Tap?
What Size is the O-Ring Fitted to a Garden Tap?


Garden Hose O’Ring Sizes:

The standard 1/2″ garden hose connectors and fittings have the following o-ring size:

O-Rings – Garden Hose Fittings
Hose Size Unit Outside Dia
Inside Dia
Cross Section

mm 16.01  10.77 2.62
5/8″ 7/16″ 7/64″
0.630 0.424 0.103
Note: EPDM rubber o-rings will last a lot longer if used sunlight.
This is only a guide, please check the parts are correct for your application.


  • EPDM rubber is best suited for garden hose o-rings, as EPDM will resist breaking down in sunlight. EPDM – Ethylene Propylene Diene Monomer (also known as EP, EPM).
  • Generally most hose connectors are the same size… But there may be some slight differences between different manufacturers.
What Size is the O-Ring Fitted to a Garden Hose Connector?
What Size is the O-Ring Fitted to a Garden Hose Connector?

How to Measure an O’Ring:

To measure an o-ring, you will need the following dimensions:

Outside Diameter (OD) & the Internal Diameter (ID)

These two measurements (OD & ID) will give you the thickness of the o-ring, (or, you can just measure it)

Cross Section (CS) Thickness = (ODID) / 2

You can use a ruler to measure an o-ring, but if you have a digital caliper, it’s so easy…


  • Old o-rings may not be the same size as what was originally fitted, as they may have stretched, or been flattened in use. However, an old o-ring can give a good indication of the size needed.
  • You can also measure the groove where the o-ring sat and the diameter of the item being measured.
    • The o-ring will always be slightly bigger than the diameter of the item being measured.
    • And slightly smaller than the groove being measured.
    • This is so the o-ring forms a seal.

Buying O’Rings:

The cheapest method of buying o-rings is often quoting the size and quantity you need, rather than buying a small pre-packaged quantity from a branded garden hose manufacturer…

Don’t forget to ask for EPDM rubber o-rings as they will last a lot longer in sunlight.

If you’re not sure what you need, sometimes it’s a good idea to have a look? The list below may give you an idea of what’s available, what to look for, and how much the part might cost…

Garden Hose Connector O-Rings and Measurement Tools:

Garden Hose Connector
O-Ring Prices
Location Item
United Kingdom UK   O-Rings
Digital Micrometer
United States USA O-Rings
Digital Micrometer
Australia AUS O-Rings
Digital Micrometer
Canada CAN O-Rings
Digital Micrometer
Ireland IRL O-Rings
Digital Micrometer
Disclosure: The links in this table are “affiliate links” This means we may garner a small commission (at no cost to you), if you choose to make a purchase.
Thank you for your support.


  • To find exactly what you’re looking for, you may have to enter the size of the o-ring, or enter text such as ‘garden hose’, as each supplier may use different text in their listing…
  • When entering the size of an o-ring as a search term, a good place to start is using the Cross Section (CS) measurement, as this is a consistent size within a listing. Don’t add the other measurements yet, as this may over limit the results (some suppliers list a range of sizes in their listing dictated by the CS).

Hope this helps… Smiley