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Stagger Check · free · no signup
Staggered tire size calculator
Compare any front and rear tire sizes. You get both overall diameters, the percentage difference, the speedometer error, and a straight verdict on whether the pairing passes the 1% rule.
// Stagger check: will these two sizes play nice?
// One-tap examples
The math
How the calculator works
A tire size like 245/45R20 encodes three numbers: section width in millimeters (245), aspect ratio as a percentage of width (45), and wheel diameter in inches (20). Overall diameter is the wheel plus two sidewalls: diameter = rim + 2 × (width × aspect ÷ 100) ÷ 25.4.
Worked example, the classic Mopar street stagger: 245/45R20 comes out to 28.68″ and 275/40R20 to 28.66″, a difference of -0.07%. That is why this pairing is the default answer on Charger and Challenger builds: the rear gains 30 mm of width while the diameters stay essentially identical.
Diameter drives everything downstream: revolutions per mile, the speedometer reading, and the wheel-speed data your ABS and stability control act on. Same math as the factory staggered database and every size page on this site, so you can verify any number we publish.
Reading the result
What the verdict means
Good pairing
Speedometer, ABS, and stability control all stay honest. The stagger is mechanically sound; the remaining question is whether your wheel widths suit both sizes.
Marginal
Drivable on a rear-wheel-drive car, but the electronics are being lied to slightly, and AWD cars should not run it at all. There is usually a better aspect-ratio pairing one click away.
Rethink it
Visible speedo error and stability-control behavior you did not sign up for. Change the rear aspect ratio to pull the diameters back together before ordering anything.
Sanity anchors
Factory pairings, run through the same math
The fastest way to trust a calculator is to feed it setups engineered by people with wind tunnels. These are factory staggered fitments from our verified database, with the diameter difference computed exactly as above:
| Car | Front | Rear | Ø diff | |
|---|---|---|---|---|
| Chevrolet Camaro SS2016-2024 | 245/40ZR20 | 275/35ZR20 | -0.5% | |
| Ford Mustang Shelby GT5002020-2022 | 305/30ZR20 | 315/30ZR20 | +0.9% | |
| Nissan GT-R (R35)2009-2024 | 255/40ZR20 | 285/35ZR20 | -0.6% | AWD, staggered from the factory |
| Nissan 370Z Sport2009-2020 | 245/40R19 | 275/35R19 | -0.5% | |
| Toyota GR Supra 3.02020- | 255/35ZR19 | 275/35ZR19 | +2.1% | Factory runs the gap; electronics calibrated for it |
| Chevrolet Corvette C8 Stingray2020- | 245/35ZR19 | 305/30ZR20 | +5.6% | Ø mixed 19″/20″ wheels by design |
Most factory staggers sit comfortably inside 1%. The exceptions prove the rule: when a factory runs a larger gap or mixes wheel diameters, the car’s electronics are calibrated for that exact pairing at the plant, a luxury an aftermarket setup does not get. Full list: the factory staggered database.
Common questions
Staggered tire math, answered
How do you calculate whether staggered tire sizes work together? Compute each tire's overall diameter: wheel diameter plus twice the sidewall height, where sidewall height is section width times aspect ratio. Compare front to rear; if the two diameters are within about 1% of each other, the pairing is mechanically sound and the remaining question is wheel width.
Will a staggered setup affect my speedometer? Only if the front and rear overall diameters differ. The car's electronics assume all four tires roll the same distance per revolution, so a diameter mismatch skews the speedometer and feeds bad data to ABS and stability control. The calculator shows the indicated reading at a true 70 mph for any pairing.
Can you run staggered tires on an AWD car? Only when the factory engineered it, the way the Nissan GT-R ships staggered with matched diameters and a driveline calibrated for the setup. Improvising a diameter mismatch on an AWD car forces the center differential to work constantly and wears the driveline. Copy the factory specification exactly or stay square.
Why does the rear aspect ratio drop as the tire gets wider? Sidewall height is a percentage of section width, so a wider tire at the same aspect ratio is also a taller tire. Dropping the rear aspect ratio brings the diameter back in line: that is why 245/45R20 pairs with 275/40R20 rather than 275/45R20.
Can I use this to compare any two tire sizes? Yes. The math is a general tire size comparison: enter any two sizes and you get both overall diameters, the difference, and the speedometer effect. The front and rear framing is because staggered setups are where a mismatch bites hardest, but the same comparison answers plus-sizing and replacement-size questions too.
Deeper dives: the full staggered guide covers wheel-width windows and the honest trade-offs, the fitment finder shows what your exact car shipped with, and the size pages break down 245/45R20 · 275/40R20 · 305/35R20.
Always confirm against the tire placard on your driver-side door jamb and your actual wheel widths before ordering. Fitments here cover common factory and community setups. Years and packages vary.
// Sources & further reading
- Tire and Rim Association (T&RA) standards · The US standards body whose yearbook defines size/rim pairing norms.
- Continental tire knowledge: rim/tire combinations (ETRTO) · How approved rim-width ranges are defined under industry standards.
- Your vehicle’s tire placard (driver-side door jamb) & owner’s manual · The legally required OEM fitment record on every car, always the first authority.
How we compile and verify fitment data: our methodology. Spot an error? fitment@staggeredsetup.com. Corrections ship fast.