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255/55R20 vs 295/50R20

295/50R20 is taller than 255/55R20 by 1.84% — a diameter difference of 0.57″.

What changes between 255/55R20 and 295/50R20

Switching from 255/55R20 to 295/50R20 changes overall diameter by +1.84%, a taller tire by 0.57 inches. This lands inside the ±3% fitment safe zone, so most vehicles will accept the swap without rubbing, speedometer recalibration, or ABS/TPMS complications. Section width moves by +1.57″ (255mm → 295mm), which affects contact patch and fender-well clearance. Sidewall height shifts by +0.29″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -12, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.2 mph. Both sizes share the same 20″ rim, so no wheel change is required — this is a pure tire-only swap.

Spec 255/55R20 295/50R20
Overall diameter 31.04″ 31.61″
Section width 10.04″ (255 mm) 11.61″ (295 mm)
Sidewall height 5.52″ (55%) 5.81″ (50%)
Rim diameter 20″ 20″
Circumference 97.53″ 99.32″
Revs per mile 650 638

Interactive comparison

Type to search · try 275/65R18 or "33" for inch aliases
Common upsizes from 255/55R20:
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255/55R20

Diameter
31.04″ / 788.5mm
Section Width
10.04
Sidewall
5.52″ / 140.25mm
Circumference
97.53
Revs/Mile
650
See tires in 255/55R20

295/50R20

Diameter
31.61″ / 803mm
Section Width
11.61
Sidewall
5.81″ / 147.5mm
Circumference
99.32
Revs/Mile
638
See tires in 295/50R20
255/55R20 · 31.04295/50R20 · 31.61

Speedometer & Diameter Impact

Wider tire — verify wheel width
Diameter Change
+1.84%
Sidewall Change
+0.29″
Revs/Mile Δ
-12
mph

At an indicated 60 mph, your actual speed is 61.1 mph (98.34 km/h). Your speedometer reads 1.84% low versus actual speed.

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