Section Width405 mm (15.9")
Aspect Ratio42%
Rim Diameter20"
Overall Diameter848 mm (33.4")
Sidewall Height170 mm
Circumference2665 mm
405/42R20 — Buy Tires

Everything to know about the 405/42R20 tire size

Size geometry

A 405/42R20 tire has a 405mm section width and a 42% aspect ratio, mounted on a 20-inch rim. Sidewall height works out to 170.1mm (6.70") and overall outside diameter is 848.2mm (33.39"). At highway speed the tire completes about 375 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 405/42R20 is unavailable, the closest same-diameter substitutes on the same rim are 395/43R20 and 415/41R20. Both keep your speedometer reading within 1% — safe for daily use, ABS, and stability control. Always verify load and speed ratings before swapping.

Plus / minus sizing options

For a 405/42R20 you can upsize to 415/38R21 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 395/46R19 (minus-one) for a softer ride or winter setup. Both stay inside the Âą3% diameter tolerance that ABS and TPMS systems expect.

Vehicle compatibility

0 vehicles in our database run the 405/42R20 tire size from the factory. Aftermarket fitment depends on rim width, offset, and clearance — match these specs to your wheel before purchasing tires.

Vehicles Using 405/42R20

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