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215/40R18 vs 265/30R19

265/30R19 is taller than 215/40R18 by 1.97% — a diameter difference of 0.49″.

What changes between 215/40R18 and 265/30R19

Switching from 215/40R18 to 265/30R19 changes overall diameter by +1.97%, a taller tire by 0.49 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 +1.97″ (215mm → 265mm), which affects contact patch and fender-well clearance. Sidewall height shifts by -0.26″: a shorter sidewall sharpens steering response at the cost of ride comfort and rim protection. Revs per mile moves by -16, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.3 mph. The swap also changes rim diameter from 18″ to 19″, meaning new wheels are required. Wheel cost typically dominates the total upsize budget.

Spec 215/40R18 265/30R19
Overall diameter 24.77″ 25.26″
Section width 8.46″ (215 mm) 10.43″ (265 mm)
Sidewall height 3.39″ (40%) 3.13″ (30%)
Rim diameter 18″ 19″
Circumference 77.82″ 79.36″
Revs per mile 814 798

Interactive comparison

Type to search · try 275/65R18 or "33" for inch aliases
Common upsizes from 215/40R18:
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215/40R18

Diameter
24.77″ / 629.2mm
Section Width
8.46
Sidewall
3.39″ / 86mm
Circumference
77.82
Revs/Mile
814
See tires in 215/40R18

265/30R19

Diameter
25.26″ / 641.6mm
Section Width
10.43
Sidewall
3.13″ / 79.5mm
Circumference
79.36
Revs/Mile
798
See tires in 265/30R19
215/40R18 · 24.77265/30R19 · 25.26

Speedometer & Diameter Impact

Different rim — new wheels requiredWider tire — verify wheel width
Diameter Change
+1.97%
Sidewall Change
-0.26″
Revs/Mile Δ
-16
mph

At an indicated 60 mph, your actual speed is 61.18 mph (98.46 km/h). Your speedometer reads 1.97% low versus actual speed.

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