What offset means and why it matters for your rims

Offset is the distance in millimeters between the wheel's mounting surface and its centerline. It determines how far your rim sits in or out from your vehicle's hub. If you install rims with the wrong offset, your wheels can rub against the suspension, brake components, or the inside of the fender — or they can stick out too far and look wrong. Finding your rim's offset tells you whether they will fit safely on your vehicle.

Offset is stamped directly on every rim and is also listed on the paperwork that came with aftermarket wheels. If you bought used rims or inherited them, you may need to read the stamp yourself or contact the manufacturer. The offset number always appears as a positive or negative value — for example, +45 or -12 — and is measured in millimeters.

Key Takeaways

  • Offset is stamped on the back of every rim and shows how far the wheel sits from the hub, measured in millimeters.
  • The stamp appears as a series of numbers and letters that includes the offset value, usually preceded by "ET" or just shown as a number with a plus or minus sign.
  • Your vehicle's correct offset is listed in the owner's manual, on a sticker inside the driver's door jamb, or on the sidewall of your original tires.
  • Offset varies by vehicle model and year, so you must match your specific car's requirement, not just assume all rims of the same size will work.

Reading the offset stamp on the rim itself

Turn the rim so the back face is visible to you. You will see a series of numbers and letters stamped or cast into the metal. The offset value is part of this stamp and is usually marked with "ET" followed by a number — for example, "ET45" means an offset of +45 millimeters. Some rims use just the number with a plus or minus sign, like "+35" or "-10".

The full stamp typically includes the rim width, diameter, offset, and the manufacturer's name or logo. For example, a complete stamp might read "8.5J x 19 ET35 5x120" — meaning the rim is 8.5 inches wide, 19 inches in diameter, has an offset of +35 millimeters, and has a 5-bolt pattern with 120-millimeter bolt circle diameter. The offset is the number that comes after "ET" or stands alone with a plus or minus sign.

If the stamp is worn, faded, or difficult to read, take a photo with good lighting and zoom in on your phone. If you still cannot read it, contact the rim manufacturer with the rim's diameter and width — they can often identify the offset from those measurements and their production records.

Finding offset information from the rim's paperwork or receipt

If you bought the rims new or have the original paperwork, the offset will be listed on the invoice, product box, or specification sheet. Look for a line that says "Offset" or "ET" followed by a number. Aftermarket wheel retailers and manufacturers always include this information because buyers need it to verify fitment before purchase.

If you have the rim's model name or part number, you can search the manufacturer's website or call their customer service line. Provide the model name, diameter, and width, and they will give you the offset. Many wheel manufacturers also maintain online catalogs where you can search by model number and see the full specifications.

Checking your vehicle's correct offset in the owner's manual

Your vehicle's original offset — the offset of the rims that came on your car from the factory — is listed in the owner's manual under "Wheels and Tires" or "Specifications." This is the offset your vehicle was engineered to use, and it is the baseline for deciding whether aftermarket rims will fit.

If you do not have the manual, check the driver's side door jamb for a sticker that lists tire and wheel information. This sticker often includes the original rim size and offset. You can also look at the sidewall of your current tires — the tire size is printed there, and some vehicles list the rim offset nearby.

If you cannot find the offset in any of these places, contact your vehicle's manufacturer with your vehicle identification number (VIN). They can tell you the factory offset for your specific year, make, and model. This information is free and takes a few minutes on the phone.

Understanding positive and negative offset

Positive offset means the mounting surface is closer to the outside edge of the rim, so the wheel sits further inward toward the vehicle's center. Most modern passenger cars and SUVs use positive offset, typically between +30 and +50 millimeters. A higher positive number (like +50) pushes the wheel further in.

Negative offset means the mounting surface is closer to the inside edge of the rim, so the wheel sits further outward away from the vehicle's center. Negative offset is common on performance vehicles and some trucks. A more negative number (like -10) pushes the wheel further out.

Changing offset changes how the rim sits relative to your suspension and fenders. If you install rims with offset that is too positive, the wheel moves inward and may rub the suspension or brake components. If the offset is too negative, the wheel moves outward and may rub the fender or stick out beyond the vehicle's body line. Most vehicles have a range of acceptable offset — usually within 5 to 10 millimeters of the factory offset — but you should verify this with a tire shop or the vehicle manufacturer before buying new rims.

What to do if the offset is not marked or readable

If the rim is very old, heavily corroded, or the stamp has worn away completely, you have two options: contact the rim manufacturer if you know the brand and model, or take the rim to a tire shop and ask them to measure it. A tire technician can measure the rim's width and the distance from the mounting surface to the centerline, then calculate the offset.

You can also measure the offset yourself if you have the rim off the vehicle. Place the rim face-down on a flat surface. Measure from the back edge of the rim to the mounting surface (the part that bolts to the hub). Then measure the total width of the rim from back edge to front edge. The offset is the distance from the mounting surface to the centerline — which is half the total width. If the mounting surface is closer to the back, the offset is positive; if it is closer to the front, the offset is negative.

Frequently Asked Questions

Can I use rims with a different offset than my factory rims?

Yes, but only within a small range. Most vehicles can safely use rims with offset within 5 to 10 millimeters of the factory offset. Going beyond that risks rubbing suspension parts or fenders. Check your vehicle's manual or ask a tire shop what range is safe for your specific model before buying new rims.

What happens if I install rims with the wrong offset?

Rims with offset that is too positive may rub the suspension or brake components. Rims with offset that is too negative may rub the inside of the fender or stick out beyond the vehicle's body. Either problem can damage the rim, tire, or vehicle components, and may make the vehicle unsafe to drive.

Is offset the same as backspacing?

No. Offset is the distance from the mounting surface to the centerline. Backspacing is the distance from the back edge of the rim to the mounting surface. They are related but measured differently. Offset is what manufacturers list, so use offset when checking fitment.

Where do I find offset on a tire?

Offset is not printed on the tire itself — it is a property of the rim. The offset is stamped on the rim's back face or listed on the paperwork that came with the wheels. Check the rim, not the tire.

Do all rims of the same size have the same offset?

No. Two rims that are both 19 inches in diameter can have completely different offsets. Offset depends on the rim's design and manufacturer, not just its size. Always check the specific offset of the rims you are buying, even if they are the same diameter as your current rims.