What size wheels fit my car? How to find your wheel size

In short. The wheel size that fits your car is, first, the one its manufacturer lists for your exact version: in the handbook, in the maker's wheel and tyre list, and marked on the wheels the car left with. A size is written as width, diameter and offset, for example 8.5J x 19 ET52. A wheel fits only if five numbers match: the bolt pattern (PCD) and the centre bore, which the hub dictates; the diameter and the width, which must carry a tyre your car is listed for; and the offset, which decides whether the wheel clears the arch, the brakes and the suspension. The load rating and the fixings come on top. One model usually has several sets: Porsche lists at least five different front-and-rear wheel combinations for the 911 (992) in summer alone, and Tesla six wheel entries for the Model 3. So there is no single chart by make and model that you can trust on its own. To change size, start from your car's list, keep the overall diameter of the tyre close to the original, and have the PCD, bore and clearances checked for your exact car before anything is ordered.

Start from what the car left with

Three places give the original sizes, in this order of reliability.

1. The manufacturer's own list for your exact version. The owner's handbook, or the maker's wheel and tyre list. Porsche's bulletin for the 911 (992) is an example: it is headed "permissible tire and wheel sizes" and gives, for each axle, the tyre and the wheel with its width, diameter and rim offset (RO), in millimetres (Porsche bulletin 38/25).
2. The label on the car. In the United States, the safety standard requires a tire information placard on the driver's side B-pillar, which gives the size designation of the original tyres and their cold pressures; it does not give the wheel width or offset (49 CFR 571.110, S4.3). In Great Britain the handbook is the reference; some cars also carry a label at the driver's door or inside the fuel flap. The tyre size on it gives you the wheel diameter, which is the last number: 225/45 R17 is made for a 17-inch wheel.
3. The wheels themselves, if they are the ones the car left with. Porsche says its wheels carry, on the inside, the wheel size, the rim offset in mm, the part number and the logo.

Do not take the sizes from the wheels on the car if someone has changed them. Look for the sizes in the maker's document instead.

Read the markings on a wheel

The marking is on the back of a spoke or on the inside of the barrel. UN Regulation No. 124 asks the maker of a replacement wheel to mark, so that it can be read with the tyre fitted: the maker's name or trade mark, the rim designation, the offset (inset), the date of manufacture (month and year) and the part number (UN Regulation No. 124, § 5.1). The regulation's own example reads "5½ J x 14 FH 36". Here is how to read a size such as 8.5J x 19 H2 ET52.

The offset is sometimes written after the size, as in Volkswagen's example "7,0 J x 17, ET49, LK112/5", where LK112/5 is the bolt pattern, five holes on a circle of 112 mm (Volkswagen); Porsche writes it as RO, "rim offset". The sign is the same everywhere, but the PCD and the centre bore are often not marked at all: they come from the car's documents or from measuring.

How to measure a wheel with no marking

Take the wheel off the car, and the tyre off the wheel if you can. Then:

1. Diameter. It is the distance between the bead seats, the surfaces on which the tyre beads sit (RIAL), not the outside diameter of the lip. The easiest reading is the tyre's: the last number of its size is the diameter of the wheel it was made for.
2. Width. It is the distance between the rim flanges, measured on the inside faces, not across the outside of the lips. The overall width of a wheel is larger than its nominal width by about an inch (25 mm), so a wheel that measures 10.5 inches across the outside of the lips is about a 9.5J. An inch is exactly 25.4 mm (NIST), so converting between the two units adds no rounding.
3. Bolt pattern and centre bore. Count the holes and measure between hole centres, as set out in our guide to PCD, bolt pattern and centre bore; five-hole wheels need a small calculation, and the table there saves you doing it. Measure the bore with calipers.
4. Offset. From the backspacing and the overall width, with the worked examples in our guide to wheel offset.

A measurement tells you what a wheel is. It does not tell you whether it fits your car: that comes from the list below.

The five numbers that must match

Load rating and the seat of the fixings come on top: the wheel must carry at least what the car's list carries, and its bolt or nut seat must match the fixings (our guide to PCD and centre bore covers the seats). The tyre guide, how to read a tyre size, gives the tyre's side of the same list.

One car, several sizes: what manufacturers list

A make does not have one wheel size, and a model often does not either. Two documents show how much a single list can hold.

Porsche 911 (992), summer sets. The overall diameters in the last column are our arithmetic: the wheel diameter in millimetres plus two sidewalls.

The list also gives winter sets, and a second Turbo set with 9.5J x 20 RO 44 at the front and 12J x 21 RO 70 at the rear. Three things stand out. Front and rear are different sizes: the rear wheel is three inches wider than the front one, and a 20-inch rear sits beside a 19-inch front. Within a single family the offsets run from RO 38 to RO 70. And the overall diameters are not identical: between the 19/20 and 20/21 packages, the front tyre grows by 8.9 mm (1.3 per cent) and the rear by 1.9 mm (0.3 per cent); the Turbo's tyres are about 1 per cent larger than the Carrera's 20/21 ones; and the Dakar's, with its all-terrain tyres in the list, are 4 to 5 per cent larger than the Carrera's 19/20. A maker lists what it has checked for each package. It is not a tolerance that you can carry over to another car.

Tesla Model 3 (2024 on). The service manual lists these wheels:

The manual adds that wheel packages vary by region, and that the 18-inch steel wheel should not be fitted to the Premium or Performance versions (Tesla service manual). One list holds six wheels, and which of them a given car has depends on its version and its market. That is why a chart by make and model is a starting point at best, and why we ask which version you have.

If you want a different size

Everything above is the case where you stay with the list. A different size is a decision with several checks, and none of them is optional.

• The bolt pattern and the bore stay as they are. A hub ring can fill a bore that is too large. Nothing can make a wrong PCD fit.
• The tyre. Keep the load index and the speed symbol at least those your car lists, and the overall diameter close to the original, because the speedometer counts turns of the wheel. Our guide to reading a tyre size sets out how close "close" is, and the tyre size calculator compares two sizes.
• The width, within the range the tyre maker gives for your tyre size.
• The clearances. When UN Regulation No. 124 assesses a replacement wheel, it asks as a rule for at least 3 mm between the wheel and the brake components and 4 mm to suspension and steering components, in the worst case (Annex 10, § 2.1). Those are assessment criteria, not fitting advice, but they show the scale of the margin. The wheel offset calculator compares where two wheels sit; it does not say whether yours clears.
• The law and your insurer, in Great Britain. The MOT manual fails a wheel and its fixings that are not compatible, tyres of different sizes on one axle, a load or speed rating below the minimum, and a tyre fouling a part of the vehicle at the time of the test (sections 5.2.2 and 5.2.3; MOT manual). A car must also have wings to catch what its wheels throw up, so far as practicable (regulation 63(2)). Changing the wheels is a modification for the Financial Ombudsman Service, which advises telling the insurer as soon as possible (FOS). Our article on new forged wheels and the MOT sets out the rest.

Ask whoever sells you the wheels to confirm in writing that they fit your exact version, and what that is based on.

A short method

1. Find your car's list for its exact version: handbook, maker's wheel and tyre list, or the label.
2. Read the markings on your wheels and compare them with the list.
3. Check the PCD and the centre bore against your car's documents: PCD, bolt pattern and centre bore.
4. If you are changing the offset or the width, compare where the new wheel sits: wheel offset.
5. Check the tyre: how to read a tyre size.
6. Do not move the wheel out with a spacer to make a wheel fit before you have read what a spacer changes.

How it works at Onyx Forged

When you order forged wheels from Onyx Forged, you are not asked for the width, the diameter, the offset, the PCD or the centre bore: they follow from your car. You tell us the car and how you want the wheels to sit. The Onyx Forged design office works the numbers out for the car as you described it (brakes, suspension, bodywork) and checks them with you before anything goes into production; customer service sends you, on request, the width, diameter and offset of each wheel. We do not give a customer a size or an offset to pick: a figure only means something for one car, with its brakes, ride height and tyres. A different tyre or ride height can change the result, so say so.

Common mistakes

• Trusting a chart by make and model without checking the version. The Porsche and Tesla lists above each carry several sets.
• Reading the width across the outside of the lips. It is taken between the flanges, about an inch less.
• Reading the diameter as the outside of the wheel. It is the diameter at the bead seats, which is the number on the tyre.
• Matching the diameter and forgetting the bolt pattern, or taking the bolt pattern from another model of the same make.
• Copying the offset of a car that looks the same. Hubs, tracks, brakes and arches differ, sometimes between versions of one model.
• Taking a tolerance from a website. No text sets one offset tolerance for every car; the list for your car decides.

Frequently asked questions

How do I find out what size wheels my car takes?

From the maker's own list for your exact version: the handbook, the wheel and tyre list, or a label on the car; the wheels it left with carry their size and offset. The last number on the tyre size gives the diameter.

What does 8.5J x 19 ET52 mean?

A wheel with a rim 8.5 inches wide between the flanges, a J-type flange, one-piece construction (the x), a diameter of 19 inches at the bead seats, and an offset of 52 mm.

Is the wheel size the same as the tyre size?

No. The tyre size (225/45 R17) gives the tyre's width and sidewall and the diameter of the wheel it fits; the wheel size gives the wheel's width, diameter and offset. They have to match, within the range the tyre maker lists for the width.

Where is the wheel size stamped?

On the back of a spoke or on the inside of the barrel, so that it can be read with the tyre fitted; the offset is sometimes written after the size. The bolt pattern and the centre bore are often not marked.

Can I fit bigger wheels?

Only if your car's list allows it, or if the checks above pass for your exact car: the bolt pattern and bore, the load and speed rating, the overall diameter, the width, and the clearances. We give no size, because none is right for every car.

Do all four wheels have to be the same size?

No: the Porsche and Tesla lists above have wider rear wheels. What the MOT manual fails is tyres of different sizes on the same axle.

Is there a reliable wheel size chart?

A chart compiled by a website is a starting point. The reference is the manufacturer's list for your exact version, because one model carries several sizes.

What do I need to tell a wheel maker?

The make, model and exact version of the car, how you want the wheels to sit, and any change of tyre or ride height. At Onyx Forged the rest follows from the car.

Where to go next

For where a wheel sits, see wheel offset; for how the wheel is fixed, PCD, bolt pattern and centre bore; for the tyre, how to read a tyre size; for what a wide wheel with a low offset looks like, deep dish and concave wheels; and for how wheels differ in the way they are made, forged, cast and flow-formed wheels. Onyx Forged is a French brand of made-to-order forged wheels, designed to JWL/VIA standards: see Onyx Forged and the catalogue.

Sources

• Porsche AfterSales, bulletin 911 (992) 38/25, wheels and tyres list (7 October 2025); Tesla Model 3 service manual 2024+, Wheels.
• UN Regulation No. 124, replacement wheels: § 5.1, Annex 3 and Annex 10 § 2.1; ISO 3911:2021, vocabulary, designation and marking (free preview).
• RIAL, Composition of a Wheel Rim (14 February 2020); Volkswagen, Felgenkennzeichnung (in German).
• 49 CFR 571.110, FMVSS No. 110, S4.3, the tire information placard.
• GOV.UK, MOT inspection manual, section 5; The Road Vehicles (Construction and Use) Regulations 1986, regulation 63; Financial Ombudsman Service, car modifications and insurance (1 October 2024).
• NIST SP 811, appendix B.9, conversion factors.

All pages were read on 15 October 2026.

The Onyx Forged design office.