Converting Metric Tire Sizes to Inches
#1
Converting Metric Tire Sizes to Inches
Guys,
Thought this may help everyone who is contemplating replacing their tires or wheels or both. I used this to calculate the actual tire diameter of my OEM 255/70x16 Goodyear tires at 30.06"
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"Performance Formulas:
You can calculate nominal dimensions by using the following calculation. Individual tires may vary slightly from these dimensions.
Using tire size of 235/60 R H 15 as an example.
TO CONVERT TIRE SECTION WIDTH IN MILLIMETERS TO INCHES:
Section width in millimeters ÷ 25.4 (standard metric conversion formula) = Section width in inches
EXAMPLE:
235 ÷ 25.4
= 9.25" nominal section width
TO CALCULATE TIRE SECTION HEIGHT:
Section width x aspect ratio percentage=section height
EXAMPLE:
9.25 x 60% = 5.55" nominal section height
TO CALCULATE NOMINAL OVERALL TIRE DIAMETER:
(section height x 2) + wheel diameter = overall tire diameter
EXAMPLE:
(5.55 x 2) + 15 = 26.1" nominal overall diameter"
***************
Borrowed from this web site which incidentally has other excellent technical tire information.
http://www.tyres1.com/tech.html
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Dunbarton "The Middle Aged Kid" '99 XLT SC SB 4x2 4.6 auto 3.55 ls The occasional Z-71 Eater! Wedgewood & Denim, SuperChipped, Airaid FIPK, HD electrical and cooling, power seat, Rhino Liner, Extang Classic tonneau cover, Mobil 1. Man, I got it all! (New Jersey)
Thought this may help everyone who is contemplating replacing their tires or wheels or both. I used this to calculate the actual tire diameter of my OEM 255/70x16 Goodyear tires at 30.06"
****************
"Performance Formulas:
You can calculate nominal dimensions by using the following calculation. Individual tires may vary slightly from these dimensions.
Using tire size of 235/60 R H 15 as an example.
TO CONVERT TIRE SECTION WIDTH IN MILLIMETERS TO INCHES:
Section width in millimeters ÷ 25.4 (standard metric conversion formula) = Section width in inches
EXAMPLE:
235 ÷ 25.4
= 9.25" nominal section width
TO CALCULATE TIRE SECTION HEIGHT:
Section width x aspect ratio percentage=section height
EXAMPLE:
9.25 x 60% = 5.55" nominal section height
TO CALCULATE NOMINAL OVERALL TIRE DIAMETER:
(section height x 2) + wheel diameter = overall tire diameter
EXAMPLE:
(5.55 x 2) + 15 = 26.1" nominal overall diameter"
***************
Borrowed from this web site which incidentally has other excellent technical tire information.
http://www.tyres1.com/tech.html
------------------
Dunbarton "The Middle Aged Kid" '99 XLT SC SB 4x2 4.6 auto 3.55 ls The occasional Z-71 Eater! Wedgewood & Denim, SuperChipped, Airaid FIPK, HD electrical and cooling, power seat, Rhino Liner, Extang Classic tonneau cover, Mobil 1. Man, I got it all! (New Jersey)