Tire Size Calculation
Tire Size Calculation
This page is where you can find out what tire size you should go to if you are wanting to go from your current 15 inch stock wheels to a Plus1, Plus2, or Plus3 wheel/tire combination. To figure out what will work and what will not, lets look at this calculation:
215/60ZR15 Lets say that this is your stock tire measurement. To find out what size diameter your tire is you need to:
1. Take 215 and multiply it by .60 (60 series tires) This would give you 215x.60=129.
2. Take that number and double it. This would give 129+129=258.
3. Now take that number and divide it by 25.4. That would give you 258/25.4=10.15 inches. That is the height of your sidewall of the tire.
4. Next, add your wheel size (15, 16, 17, 18....) to the number you just got. That would give us 10.15+15= 25.15 inches
Great you say, 25.15 inches, I can just about do anything with that number can't I? How will this benefit me? Well you just found out how to measure how long it takes your wheel to make one revolution. Now, if you want to figure out what will happen if you put on a larger size wheel and some lower profile tires you can plug in your wheel/tire combination and see what will be the outcome.
For example, lets say that you go up to a 235/45ZR17. To figure out what would happen to your speedometer reading you would plug it into the same calculation.
235x.45= 105.75+105.75= 211/25.4= 8.30+17= 25.30 inches
Now that number went up to 25.30 inches, that means that it takes 25.30 inches to make one revolution instead of 25.15 inches with your stock wheels and tires. This means that with the larger wheel and tire package that you have outfitted your Maxima with now makes your speedometer and odometer read a little slower than it is going in all actuallity. You gasp and say to yourself,"If my speedometer and odometer are going to read slower than it is actually showing, isn't that bad?" Not really because the difference between your stock tire diameter and your modified tire diameter is a very small fraction= less than 1/10 an inch. This little amount of difference won't make a significant amount of impact on your speed and odometer readings to be overly concerned about, but you should know that it does make a minor difference.
Some other tire/wheel calculations that I have done are:
205/65ZR15= 205 x .65 = 133.25 + 133.25 = 266.5/25.4 = 10.49 + 15 = 25.49
215/60ZR15= 215 x .60 = 129 + 129 = 258/25.4 = 10.15 + 15 = 25.15
225/60ZR15= 225 x .60 = 135 + 135 = 270/25.4 = 10.62 + 15 = 25.62
235/60ZR15= 235 x .60 = 141 + 141 = 282/25.4 = 11.10 + 15 = 26.10
205/50ZR16= 205 x .50 = 102.5 + 102.5 = 205/25.4 = 8.07 + 16 = 24.07
225/45ZR16= 225 x .45 = 101.25 + 101.25 = 202.5/25.4 = 7.97 + 16 = 23.97
225/50ZR16= 225 x .50 = 112.5 + 112.5 = 225/25.4 = 8.85 + 16 = 24.85
225/55ZR16= 225 x .55 = 123.75 + 123.75 = 247.5/25.4 = 9.74 + 16 = 25.74
235/50ZR16= 235 x .50 = 117.5 + 117.5 = 235/25.4 = 9.25 + 16 = 25.25
245/45ZR16= 245 x .45 = 110.25 + 110.25 = 220.5/25.4 = 8.68 + 16 = 24.68
245/50ZR16= 245 x .50 = 122.5 + 112.5 = 245/25.4 = 9.64 + 16 = 25.64
215/40ZR17= 215 x .40 = 86 + 86 = 172/25.4 = 6.77 + 17 = 23.77
215/50ZR17= 215 x .50 = 107.5 + 107.5 = 215/25.4 = 8.46 + 17 = 25.46
225/50ZR17= 225 x .50 = 112.5 + 112.5 = 225/25.4 = 8.85 + 17 = 25.85
235/40ZR17= 235 x .40 = 94 + 94 = 188/25.4 = 7.40 + 17 = 24.40
235/45ZR17= 235 x .45 = 105.75 + 105.75 = 211.5/25.4 = 8.32 + 17 = 25.32
245/40ZR17= 245 x .40 = 98 + 98 = 196/25.4 = 7.71 + 17 = 24.71
245/45ZR17= 245 x .45 = 110.25 + 110.25 = 220.5/25.4 = 8.68 + 17 = 25.68
245/50ZR17= 245 x .50 = 122.5 + 122.5 = 245/25.4 = 9.64 + 17 = 26.64
215/40ZR18= 215 x .40 = 86 + 86 = 172/25.4 = 6.77 + 18 = 24.77
225/40ZR18= 225 x .40 = 90 + 90 = 180/25.4 = 7.08 + 18 = 25.08
225/45ZR18= 225 x .45 = 101.25 + 101.25 = 202.5/25.4 = 7.97 + 18 = 25.97
235/35ZR18= 235 x .35 = 82.25 + 82.25 = 164.5/25.4 = 6.47 + 18 = 24.47
235/40ZR18= 235 x .40 = 94 + 94 = 188/25.4 = 7.40 + 18 = 25.40
235/45ZR18= 235 x .45 = 105.75 + 105.75 = 211.5/25.4 = 8.32 + 18 = 26.32
235/50ZR18= 235 x .50 = 117.5 + 117.5 = 235/25.4 = 9.25 + 18 = 27.25
245/40ZR18= 245 x .40 = 98 + 98 = 196/25.4 = 7.71 + 18 = 25.71
245/45ZR18= 245 x .45 = 110.25 + 110.25 = 220.5/25.4 = 8.68 + 18 = 26.68
Back to my Modifications page.