Tire Size Calculator

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Current Tire: 145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 345 355 375 395 20 25 30 35 40 45 50 55 60 65 70 75 80 85 10 12 13 14 15 16 16.5 17 17.5 18 19 19.5 20 21 22 23 24 25 26 28 30 (section width, aspect ratio, wheel size in inches)	New Tire: 145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 345 355 375 395 20 25 30 35 40 45 50 55 60 65 70 75 80 85 10 12 13 14 15 16 16.5 17 17.5 18 19 19.5 20 21 22 23 24 25 26 28 30 (section width, aspect ratio, wheel size in inches)
Tire Image Link: Tire Tool Link: Select a current tire size to view other possible matches with different sizes (within +- 3% of the current tire's size)
This tool should only be used as a reference. You should always verify the sizing information with the actual tire maker or your car's manufacturer to guarantee a safe and proper fit.

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Tire Age Calculator

DOT Tire Age calculator

Calculating the age of your tires is rather simple despite the age being somewhat hidden on the tires. Since 2000 all tires have a DOT Age on them (and many before 2000 as well). It is located at the end of the line of text that begins with DOT as shown in the image below: The 4202 in this image means that the tire was made in the 42nd week of 2002. While somewhat debated, some research indicates that tires older than six years have an increased chance of failing. (Over 100 deaths in the US have been directly attributed to driving on tires that are too old). However, keeping all tires properly maintained is the most important thing you can do for your tires regardless of age.

Enter your tire's DOT Age Code and click submit:

If your tire's DOT age is older than: you may want to consider changing them. (ie: 1204 is older than 2204 which is older than 2205)

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Tire Guide Database statistics:

To give you an idea of how the average tire in our Tire Guide DB rated:
Treadwear ratings: 4157 tires above 300, 3937 tires below 300, Unrated: 1698
Traction ratings: AA: 2475, A: 4014, B: 193, C: 152 Unrated: 1698
Temperature ratings: A: 5301, B: 1518, C: 15, Unrated: 1698

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DOT and NHTSA documents

While perusing the good old DOT and NHTSA sites I came across a few worthwhile studies on tire safety, saving gas, odometer fraud, oversizing tires, and relative insurance costs. If you are interested in reading any of them you can find them below:

1. Tire Safety - most of the usual stuff that most people will be aware of. However, it is always good to get a refresher and to check once and awhile. Includes tips like checking air pressure, checking valve caps, don't exceed load index, penny test and so on.
2. Oversizing - interesting research on oversizing your tires and braking.
3. Relative insurance costs - interesting study on sent to car dealers about differences in insurance costs based on damage susceptibility for the vehicle.
4. Odometer fraud - explains how over 450,000 cars are sold with fraudulent odometer readings and how to help spot possible fraud situations.
5. Saving gas - mostly basic tips on saving gas. Funny enough the first one is to walk, bike, or take a bus! However, there are useful tips like keeping tires properly inflated (very important for a number of reasons!) and other things that I have found people do not do enough.