Gear Ratio Calculator

Gear Ratio Calculator

Ring Gear:
Pinion Gear:
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Gear Ratio Formula:

Gear Ratio = Ring Gear / Pinion Gear

Gear Ratio Definition

The gear ratio refers to the number of times the ring gear spins compared to the number of times the pinion gear spins. This sounds easy, but when it comes to figuring out the gear ratio, how can you be sure you have the right numbers for your calculations? The surefire way is to go inside, wash your hands, and use our free online calculator, and take out all the hassle!

What’s the Risk of a Bad Gear Ratio?

You want to make sure that your gear ratios match the specs that come with your car, because most people think gear ratios are unimportant but the gear ratio is closely tied into RPM’s which also ties into fuel efficiency. If the gear ratios are off, that can lead to engine trouble, seizure of the engine, increased fuel consumption and other road hazards. Therefore, it is important to know your proper gear ratios, not only at low gears but also as you get the engine to higher gears. If the gears spin too fast, what could happen could spell total disaster.  While you are at it, take a look at our RPM Calculator.

Why Use Our Calculator?

Sure, the calculation is very easy, but how many times have you been inside of a garage and that perfect piece of paper gets smudged with oil or thumbprints and you can’t make out the numbers, or worse, calculating it when the engine is running could break your concentration. Gas powered engines are loud, so instead of risking having ear trouble while calculating or possibly dropping your calculator into the engine and watching it shatter, instead do it in the safety of sitting at your computer desk and write in the numbers instead.

How to Use Our Calculator

Calculations are simple. Once you’ve set a predetermined time (such as ten seconds), count the number of times each of the gears rotates, then simply go to our web site and type the following:

  • Input the number of times the ring gear rotates.
  • Input the number of times the pinion gear rotates.
  • Press the calculate button.

Within seconds, you will have your proper gear ratio in hand. And once you check it against your manual, you’ll find out how well the engine is in fact running.


Why not take our gear ratio calculator and introduce it to all of your do-it-yourselfer friends by posting it on Facebook, Twitter or Digg and having them figuring out their gear ratios from visiting your page? Another option is to download a widget and paste it on your website, which would be a nice bonus for people who already like fixing up cars and making sure that their gear ratios are correct.

A gear ratio calculator is very handy if you want to make sure your engine is running properly and with gas prices likely to be high for a long time to come, it’s also useful for helping you determine if the problem lies with the way your engine is running. So use our free calculator and get the results you need with no mess and no oily hands.

How to Calculate Gear Ratio

Let's be honest - sometimes the best gear ratio calculator is the one that is easy to use and doesn't require us to even know what the gear ratio formula is in the first place! But if you want to know the exact formula for calculating gear ratio then please check out the "Formula" box above.

Add a Free Gear Ratio Calculator Widget to Your Site!

You can get a free online gear ratio calculator for your website and you don't even have to download the gear ratio calculator - you can just copy and paste! The gear ratio calculator exactly as you see it above is 100% free for you to use. If you want to customize the colors, size, and more to better fit your site, then pricing starts at just $29.99 for a one time purchase. Click the "Customize" button above to learn more!