Find all compatible tire sizes when upgrading to +1, +2, or +3 inch larger rims. Maintains overall diameter within ±3% for accurate speedometer readings.
The Plus Sizing Guide is an intelligent curation tool that helps you find the optimal tire size combinations for increasing your wheel diameter while maintaining the vehicle's overall tire outer diameter. Successful plus-sizing enhances a vehicle's aesthetic appeal and improves cornering stability and steering response, but incorrect sizing can lead to poor fuel economy, harsh ride quality, and even errors in electronic control systems.
Based on your original tire specifications, the system searches thousands of combinations for +1, +2, and +3 inch wheels in its database. It filters for results within a ±3% overall diameter discrepancy, prioritizing standard, widely available sizes that won't strain the vehicle's undercarriage. Each recommendation displays the speedometer error rate and sidewall height change, allowing users to directly compare the pros and cons of each setup.
Enter your current tire size to find all compatible sizes for +1, +2, and +3 inch rim upgrades. Compatible sizes maintain overall diameter within ±3% of your original tire.
Plus sizing keeps the overall tire diameter nearly the same while using a larger rim and lower-profile tire. This improves handling and appearance.
The speedometer error column shows how much your speedometer reading will differ from actual speed with each new size.
Plus sizing trades sidewall for rim while holding overall diameter nearly constant. Worked example: 205/55R16 has a 631.6 mm diameter; the classic +1 step to 225/45R17 gives 634.3 mm, a +0.43% change — and the matching +2 step 245/40R18 lands at 653.2 mm (+3.4%), already brushing the limit. The rule of thumb is to add ~10-20 mm of section width and drop ~10 points of aspect ratio per inch of rim.
Keep the diameter delta within ±3% so speedometer, ABS, and ESP calibration stay valid; beyond that, electronic systems and clearance both suffer. A common mistake is chasing a large rim without lowering the aspect ratio enough, which pushes diameter too high and causes fender rub. Wider plus-sized tires also usually need a different wheel offset, so verify that section width plus the offset change still clears struts and fenders.
Lower-profile sidewalls transmit more impact harshness and are more vulnerable to pothole-induced rim damage, so each plus step firms up the ride and raises bent-wheel risk. Confirm the new size is an actual production fitment with adequate load index, and check that the wheel's width falls inside the tire's approved rim-width range (ETRTO publishes a measuring-rim and a permissible range for every size) rather than only matching the diameter.