Can some provide the diameter of a tire of this size PLEASE???

45mm = 1.77 inches

1.77" x 2 = 3.54"

3.54" + 17" wheel diameter = 20.54"

That is the best I can do. Later I will go out an measure my 205/40’s and add the extra 10mm

HTH,

Mike

no no no . . . 45 isn’t constant measurement it’s a percentage

205/45R17

205 mm is the width

45 is the wall of the tire as a percentage of the width

45% of 205mm = 92.25mm

92.25mm * 2 = 184.5mm

184.5mm = 7.26" (184.5/25.4)

17" + 7.26" = 24.26"

or you can let my calculator do the math for you

You are correct, I was wrong on that one. Sorry.

Mike

205/45/17 = 24.26 inches diameter

if you want to know whow its done here it is.

section width multiplied by the aspect ratio will give you a number. divide that number by 25.4 and that will equal the sidewall. multiply the sidewall number by two and then add the size of the rim and you end up with the overall diameter.

205 X 45 = 9225

9225 divided by 25.4 = 363

3.63 X 2 = 7.26

7.26 + 17 = 24.26

Originally posted by Speeddaddy

[B]205/45/17 = 24.26 inches diameter

if you want to know whow its done here it is.

section width multiplied by the aspect ratio will give you a number. divide that number by 25.4 and that will equal the sidewall. multiply the sidewall number by two and then add the size of the rim and you end up with the overall diameter.

205 X 45 = 9225

9225 divided by 25.4 = 363

3.63 X 2 = 7.26

7.26 + 17 = 24.26 [/B]

This sounds correct as the garage quoted me today 24.3".

Thanks everybody for your feedback

Originally posted by Speeddaddy

[B]205/45/17 = 24.26 inches diameter

if you want to know whow its done here it is.

section width multiplied by the aspect ratio will give you a number. divide that number by 25.4 and that will equal the sidewall. multiply the sidewall number by two and then add the size of the rim and you end up with the overall diameter.

205 X 45 = 9225

9225 divided by 25.4 = 363

3.63 X 2 = 7.26

7.26 + 17 = 24.26 [/B]

yeah that’s what I said! My math teachers used to always tell me to show my math . . . I guess I’ll never learn. Thanx for posting the how-to

It’s amazing how easy it is, yet it’s one of those things that most people don’t know how to calculate . . … I guess it’s the whole mixing of metric and standard units of measurement thing?

Steve

http://www.miata.net/garage/tirecalc.html

Tire size calculator in addition to percentage calculator to compare between original and other sized ur considering… best part is it shows the difference in speedometer reading.

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tire size calculation