Your tyre size can be found on the side wall of the current tyres you would like to have replaced. You will see a combination of characters in a form similar to: 195/60R15 88H meaning:
- 195 - width of tyre in millimetres.
- 60 - aspect ratio of the tyre profile (height of the side as a percentage of the width). So this aspect ratio is 60% of 195 millimetres.
- R15 - R means that it’s a radial tyre, the following two digits are the diameter of the wheel in inches.
- 88 - load index.
- H - speed index.
You can also search your vehicle for the manufacturers placard to find a suggested tyre size. From 1973 onwards, all cars are fitted with a tyre placard (usually located in the glove box, the engine bay or on a door pillar) which specifies the wheel and tyre combinations recommended by the vehicle manufacturer. The placard also specifies load capacity, speed rating and the recommended air pressure of tyres. The size you are looking for on the tyre should read something similar to “215/60R16 95V”.
Sometimes sizes will have some letters after the rim size, such as 'C' or 'LT', these stand for Commercial and Light Truck. If a tyre size has this marking, it needs to meet your vehicles requirements for them to be fitted. The placard should specific if you require C or LT tyres.
If they do not match, it may be that you or a previous owner has fitted after market rims.