EVERY MARKET, EVERY NOTATION

Tyre size calculator

Read what the size on your sidewall means, and see exactly what changing to another size does to the diameter, the speedometer and the ride height. Results in millimetres and inches, km/h and mph.

Find your vehicle's size

A tyre-only register, separate from the MyMotorInfo vehicle catalogue, holding corroborated vehicle-and-size records for any market. A size appears here only when at least two independent sources state it. OEM labels additionally require an agreeing vehicle-manufacturer source; otherwise the size remains clearly unclassified. Every answer lists its sources and source type.

The register currently holds 69 published fitments across 12 makes, with 1 more collected but withheld by the evidence gates. It is being filled make by make, so a vehicle missing here has not been collected yet — it does not mean no size exists. Whatever it says, the sidewall on your own vehicle and the door placard are the authority.

Copy it from the sidewall, the door placard or the owner's manual.

Fill this in to see what changing size does to the wheel.

Show first inMillimetresInchesBoth are always shown.

Or start from one of these

205/55 R16 91VP215/65R17LT265/70R17 121S33x12.50R15215/65 R16C90/90-12 54J2.75-18 42P25-622

Before you buy

Always confirm the tyre specification on your current tyre sidewall, the driver's door placard or your owner's manual before you buy. Where they differ from anything shown here, the vehicle manufacturer's specification is the one to follow. A size that fits the wheel is not the same as a size the manufacturer approves, and in many countries only an approved size is road legal.

Common questions

What do the numbers on a tyre mean?
On a metric size such as 205/55 R16, 205 is the section width in millimetres, 55 is the sidewall height as a percentage of that width, R marks radial construction and 16 is the wheel diameter in inches. Any load index and speed rating follow the size.
Does this work outside India?
Yes. The calculator reads the notation printed on the tyre, not the country the reader is in. ISO metric sizes used across Europe, Asia, Africa, Latin America and Australia are read, as are the P-metric, light truck and high-flotation markings used in North America, and inch-coded motorcycle and bicycle sizes. Every result is given in both millimetres and inches, and every speed in both km/h and mph.
How much can a replacement tyre size differ?
A replacement size is conventionally kept within about 3 per cent of the original overall diameter, because a larger change moves the speedometer, the odometer and the ride height. That is a rule of thumb, not an approval: only the sizes the vehicle manufacturer lists are approved for the vehicle, and in many countries only an approved size is road legal.
Where do I find my tyre size?
It is moulded into the tyre sidewall. Most cars also carry it on a placard inside the driver's door frame, inside the fuel filler flap or in the owner's manual, together with the load index and speed rating the vehicle requires.

Looking for tyres to buy rather than the size itself? The tyre finder matches a size against the products MyMotorInfo has published, and the tyre section lists them by brand.

Dimensions from the nominal size. The figures here are worked out from the size as printed, not measured on a fitted tyre, and tyre makers publish their own measured diameters. The sizes your vehicle manufacturer approves are the ones that govern warranty, insurance and road legality.