Buying a new cylinder lock? Read our guide.

Cylinder locks play an important part in your home or office security. This straightforward guide will tell you all you need to know before you buy.

How to Measure Euro & Oval Cylinder Locks

When measured correctly, replacing your cylinder locks can improve your home security. Learn how to quickly measure Euro & oval cylinder locks with our handy guide, and get the perfect fit every time.

Measuring to replace a cylinder

Replacing a cylinder? Print out our Measuring Tool and place your cylinder where indicated to get the exact dimensions.

When A and B are the same dimension, you need an Equal Cylinder. If they're different, you need an Off-Set Cylinder.

Download Measuring Tool

Measuring for a new cylinder

If you're measuring for a new door, you'll need to consider the door's width and any door furniture, such as handles or escutcheons.

Measure from the outside edge of the door (including furniture) to the centre of your door. This is dimension A and is called the External Size to Centre.

Next, measure from the inside edge of your door (including furniture) to the centre of your door to find dimension B, the Internal Size to Centre.

As a final check, measure from the outside edge to the inside edge (including all furniture) to find dimension C called the Overall Length.

If you've measured correctly the overall length, C, will be dimensions A and B combined.

For an extra helping hand, check out our How to measure a cylinder video below.