CALCULATORS FOR WHEELS, RIM WIDTH, OFFSET AND ROLL PERIMITER
Here you can get help calculating wheel-sizes, offset (et), roll perimeters & rim widths.

Wheels, Roll Perimeter & Rim Width Calculator

Tyre Size to Compare	Diameter	Circumference	Suggested Rim Width
Front Size 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 345 355 0 20 25 30 35 40 45 50 55 60 65 70 75 80 0 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Rear Size 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 345 355 0 20 25 30 35 40 45 50 55 60 65 70 75 80 0 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Difference %

0.5%1.0% 1020

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Wheels & Roll Perimeter Calculator

	TIRE WIDTH	PROFILE	WHEEL DIAMETER
ORIGINAL TIRES	145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 345	20 25 30 35 40 45 50 55 60 65 70 75 80 85	12 13 14 15 16 17 18 19 20 22 24
NEW TIRES	145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 345	20 25 30 35 40 45 50 55 60 65 70 75 80 85	12 13 14 15 16 17 18 19 20 22 24

	Height	Profile	Roll Perimeter		Height	Profile	Roll Perimeter
ORIGINAL TIRES (CM)				DIFFERENCE (CM) *
NEW TIRES (CM)				DIFFERENCE (%) *

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Offset (ET), Wheels & Roll Perimeter Calculator

			TIRE WIDTH	PROFILE	WHEEL DIAMETER
Current Wheel Width  inches	Current Wheel Offset  mm.	ORIGINAL TIRES	145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 345	20 25 30 35 40 45 50 55 60 65 70 75 80 85	12 13 14 15 16 17 18 19 20 22 24
New Wheel Width  inches	New Wheel Offset  mm.	NEW TIRES	145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 345	20 25 30 35 40 45 50 55 60 65 70 75 80 85	12 13 14 15 16 17 18 19 20 22 24

Based on your stock wheel setup, your new wheel will have:
	Diameter		Difference
ORIGINAL TIRES (IN.)		INCHES (IN.)		Speedo @60mph will read: mph
NEW TIRES (IN.)		PERCENT (%)

* Difference of roll perimeter should not be more- or less than 2.0% from standard (between new and original tires).
Corvette C6’s differ approx. 4.3% in roll perimeter between front and rear tires by default. They MUST NOT be the same.
Always use difference between original front and rear tires as reference!

Disclaimer – Information and calculators above have been collected from many sources, and are not verified.

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Suggested Rim Size & Bolt Pattern from Wheel-Size.com

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