GEAR RATIO CALCULATOR

Need help? Call 805 562 8600
    or email us

Need help? Call 805 562 8600

The right gearing combination can breathe new life into your car.

Tip 1

Here are some considerations:

  1. A car that is driven in the dirt or has tall tires might need lower gears than street car.
  2. Tall top gears can decrease engine noise on the highway and increase fuel mileage. Be careful not to choose a taller gear ratio than your engine will be able to pull.
  3. Engines that run at high RPM with narrow power bands will need much closer gear ratios than low revving engines that have broad torque curves.
Need help? We do this every day. Call us at 805 562 8600 or email us.

NOTE:
Vehicle speeds represented by this calculator are theoretical. Variables such as traction, wind resistance, and tire growth have a considerable effect on your vehicle's actual top speed

Use this gear ratio calculator to select the best ring & pinion and gear ratio combinations to serve your needs.
Check the theoretical vehicle speeds, RPM drops per gear and mile per hour pulls.

Print
Step 1 - Enter the following
Ring and Pinion Ratio
Tip 2

Ring & Pinion Ratios

Enter your ring and pinion ratio. The value must be between 1.00 and 9.99
Tire Height (inches)
Tip 3

The most accurate way to measure your tire height

  1. Mark the tire sidewall and a corresponding spot on the floor.
  2. Roll the tire until the mark on the sidewall comes back to the floor and mark the floor again
  3. Measure the distance between the marks on the floor - this is the tire's circumference.
  4. To find the tire diameter, use this formula: Circumference ÷ 3.14 = Diameter.
  5. The diameter is the height of your tire
Upshift RPM
Tip 4

Upshift RPM

This is the RPM which you will shift gears while accelerating. Normally you want this number to be at or slightly above the RPM at which the motor produces peak horsepower.
Step 2 - Enter Gear Ratios
Gear Ratio R&P Ratio Overall
Drive Ratio
Tip 5

Overall Drive Ratio

Overall Drive Ratio for each gear is simply the R&P ratio multiplied by the gear ratio.
1st
2nd
3rd
4th
Gear Ratio R&P Ratio Overall
Drive Ratio
Tip 5

Overall Drive Ratio

Overall Drive Ratio for each gear is simply the R&P ratio multiplied by the gear ratio.
5th
6th
7th