Wheel Spacer Calculator
A spacer is negative offset: a 25 mm spacer moves the wheel out exactly 25 mm. This tool shows the effect, finds the size you need for a target offset, and — the part people skip — checks whether a slip-on spacer leaves your lug nuts enough thread.
1. Effect of a spacer
2. Stud engagement check (slip-on spacers)
A slip-on plate sits between hub and wheel, so every millimeter of spacer is a millimeter less stud for the nut. Measure both figures on your vehicle.
Safety-critical. The engagement rules
here (at least one stud diameter of thread, and at least 6½ turns) are standard
engineering rules of thumb; your spacer or stud manufacturer's specification
overrides them. Torque to OEM spec, re-torque after 50–100 miles, and never stack
slip-on spacers. Spacers over ~12 mm should be bolt-on, hub-centric type.
Slip-on vs bolt-on
- Slip-on (3–12 mm): a plain plate over the OEM studs. Cheap and simple, but it consumes stud length — run the check above. If it fails, the fix is extended studs, not tighter nuts.
- Bolt-on / hub-centric (15 mm+): bolts to the hub with the OEM studs recessed inside it and provides its own studs for the wheel, so engagement is designed in. Two sets of nuts to torque. Must be hub-centric (matching center bore) so the spacer, not the studs, carries the wheel's weight.
What else a spacer changes
- Track width grows by twice the spacer (both sides). Wider track slightly improves stability but increases scrub radius and the lever arm on the wheel bearings — larger spacers wear bearings faster and can make steering tug under braking.
- Poke and fender clearance: the outer edge moves out by the full spacer thickness. Check it in the fitment calculator using the effective offset.
- Spacers cannot add offset. If you need the wheel further in, you need a higher-offset wheel.