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How to Measure Kitchen Tap Washer Size

How to Measure Kitchen Tap Washer Size

If your kitchen taps are leaky and it’s a really annoying problem, the first step is to identify the source of the problem. Most often than not, it’s the washer that needs replacing, which could be hard to do if you didn’t measure the original one correctly. The main objective is to aid people in measuring their kitchen tap washer size correctly so it can be replaced easily.

The NPSC offers valuable insight with their how to measure kitchen faucets guide. These guidelines are intended to help faucet dealers properly interpret the Kitchen Faucet specifications and to help kitchen manufacturers provide good quality faucets.

Measure tap washer size

It is not necessary to measure the washer diameter, as it is normally the same as the tap thread size. There are two main sizes of tap washers, 3/4″ and 1/2″, with some minor variations. If you have a tap with separate hot and cold handles, you will need to measure each one to determine the correct washer size needed. The easiest way to do this is to use a set of vernier calipers.

In either case, select the hole or tube that is on the side of the handle nearest to the body of the tap. It may be hidden by a screw or plug in which case this will need removing first. Measure from the inside edge of this hole or tube to the centre point of the handle spindle where it goes into the body of the tap. Make sure that you get an accurate measurement by taking several readings and averaging them. You should end up with something in between 16mm (5/8″) and 19mm (3/4″). If so then you need a 3/4″ tap washer which will fit all taps except those with 15mm (5/8″) holes.

Turn off the water supply to your tap

  • Take the cap off of the end of the spout and loosen the screw that holds the cartridge in place using a flat-headed screwdriver.
  • Remove the cartridge from the tap and take out the old washer.
  • Place the old washer on top of the new one and make sure that it is the same size.
  • If you don’t have an old washer to compare, look at how big a gap there is between the cartridge and where it meets with its housing. The washer should be big enough to fill this space comfortably, but not too big that it can’t fit in properly.

Remove the tap handle and replace with the tap spanner

If you are replacing a kitchen tap washer, you will need to know what the size of the old one is. In this step-by-step guide, we show you how to measure your existing washer or measure the opening where the washer goes.To find out what size your existing kitchen tap washer is, remove the tap handle and replace with the tap spanner. You can usually remove the handle by unscrewing it from the back. If not, then you can buy a separate spanner specifically for removing handles.

Remove the valve stem, wearing protective gloves and holding the stem with trapped water in a bucket

  • To measure the size of a kitchen, tap washer, you need to remove the valve stem, wearing protective gloves and holding the stem with trapped water in a bucket. You should turn off the main water supply and open the taps to drain any remaining water from the pipes. The washer should be measured using calipers, and if you can’t remove it, use a piece of string or paper to trace around it.
  • Remove the valve stem by turning it counterclockwise. You will need to wear protective gloves and hold a bucket under the valve before you do so. Water will come out of the valve as soon as you remove the stem, so hold tight.
  • Inspect the washer in the end of the valve stem. It is possible that your washer is worn or damaged from use. If this is the case, you will not be able to get an exact measurement using a ruler or tape measure. The easiest way to determine what size you need is to take your old washer to a local hardware store and have them match it for you.
  • Measure your old washer with a ruler if it is still in good shape. Use a caliper to get an exact measurement if possible. If your tap has two washers, inspect them both and measure each one separately.
  • Make sure that you measure your washer while it’s dry.

Measure the largest outer diameter of the valve, in millimeters

  • To measure a tap washer, remove the old tap washer and take it to your local Bunnings store. Alternatively, measure the largest outer diameter of the valve, in millimeters.
  • Measure washers from their outer edges.

Note: If you have an older style tap, it may have a fiber or rubber washer held in place by a brass screw. You will need to determine whether your tap has a fiber or rubber washer before you start.


You can measure your kitchen tap washer size after reading this guide. These washers differ in size, which influences the price. To avoid buying a product that will not fit your kitchen tap, measure it before going shopping. There are many sizes available for the same faucet model.

That is why you should always measure first, before setting out to do some shopping round.