Tire-Size-Calculator.info | Compare tires and wheels + graphical demonstration

[badger84]

Hello Forum!

I want to introduce you to my newly released tire size calculator:

www.tire-size-calculator.info

You can compare your existing and future tires and / or wheels of your vehicle. You also get a nice graphical demonstration of how the tires and / or wheels look like in comparison.

You can calculate values such as circumference, speedometer difference, changes relevant to the ride height or the effect of wheel spacers and learn which tires or wheels fit best for your car.

I hope the tire size calculator can help you with your calculations and helps you in deciding on which tires and / or wheels to choose!

Would be nice if you have any suggestions or requests how to make the tire size calculator even more better.

Greetings – Mike!



PS: Admins or mods are welcome to make this thread sticky to help also new members of the forum who could need this tire size calculator.

[CapriRacer]

Mike,

There is a problem with the calculator. The "Revs per Mile" is off.

It's off because whoever programmed the thing didn't know that the calculated free standing diameter is 97% the rolling diameter.

[badger84]

Hello Capri Racer,

i had programmed it like you said with not 100% diameter, but as i got told by other people it should be calculated with 100%. I also had a look at other calculators and most of them also calculate with 100%.

[CapriRacer]

Originally Posted by badger84

Hello Capri Racer,

i had programmed it like you said with not 100% diameter, but as i got told by other people it should be calculated with 100%. I also had a look at other calculators and most of them also calculate with 100%.

Sorry, but those folks are wrong.

Don't believe me? Look at Tire Rack and compare the stated diameters vs their revs/mile. This would be values obtained from the tire manufacturers.

And just so you know, I'm a retired tire engineer. Used to work for one of the majors - yes, you've heard of them - even in Austria.

[badger84]

Hi to everyone!

I got a lot of feedback and many of you wanted to be able to input inch-values and not only metric ones. This is now possible Hope it will help you with your calculations.

If you like the tire size calculator it would be great if you could recommend it also to others!

[CapriRacer]

Mike,

You still have a problem with the Revolutions per Mile - and it appears to be from the calculation of the rolling circumference. It needs to be 97% of the value calculated.

Compare your calculations to what is published. Tire Rack would be a good place to start.

[badger84]

CapriRacer, so you say 90% of the other tire calculators are also false? I have googled 6 random calculators and they all have the same revs/mile like mine has. I'm pretty sure there also will be a calculator which calculates with other parameters, but so you would say it's wrong how the most of it calculate?

I had a version online with other calculation parameters (the ones you told me) and i immediately got plenty of questions why my calculator is wrong compared to the others.

So what would you suggest?

[CapriRacer]

Originally Posted by badger84

CapriRacer, so you say 90% of the other tire calculators are also false? I have googled 6 random calculators and they all have the same revs/mile like mine has. I'm pretty sure there also will be a calculator which calculates with other parameters, but so you would say it's wrong how the most of it calculate?

I had a version online with other calculation parameters (the ones you told me) and i immediately got plenty of questions why my calculator is wrong compared to the others.

So what would you suggest?

Not only am I suggesting that all the other calculators are wrong, I am stating it outright and can prove it.

Just look at what is published for Revs per mile by the tire manufacturers. That's the proof.

Please note that Tire Rack is a convenient source for this data as Tire Rack gets it from the tire manufacturers and doesn't measure it themselves. (It's a bit difficult to do, so many tire manufacturers calculate it - which is why I know about this. I used to perform the calculation).

My suggestion would be to correct your calculator.

And as an aside, the reason many calculators don't fix this is that the only time it is a problem is if you use the value by itself - like when people are doing speed vs engine rpm or other gearing type issue. Comparing 2 different tire sizes has a very small amount of error - small enough that it can be ignored.

Wait!! I did think of something. Why not remove the rolling diameter from the display and fix the Revs per Mile calculation - and then when people point out the difference to other calculators (which they are not likely to do), point them to Tire Rack and say your values closely match theirs. Put another way, those other calculators give wrong answers and it doesn't appear that this fact impacts how those programmers reacted. BTW, I have pointed out this to those web sites where those calculators are - and basically got no response. If they aren't interested in being correct, fine. But I think it would be best if your calculator is correct, even if it is different.