Gear Ratio Calculator

 
Select Transmission :
Engine RPM : Enter your desired RPM for racing or cruising here.
Axle Ratio : Enter your rear axle ratio here.
Tire Height (in) : Enter your tire height here. Use the Aspect Ratio calculator below if you do not know your tire height.
  Ratio MPH  
1st Gear The estimated speed you will be traveling based on the parameters you established and the transmission you selected.
2nd Gear
3rd Gear  
4th Gear  
5th Gear  
6th Gear  

ASPECT RATIO CALCULATOR: Find your tire height using this calculator.

Enter the tire width in millimeters, the aspect ratio, the wheel diameter in inches, and Click on Calculate
Tire Width (mm) Wheel Diameter (in)
Aspect Ratio (1-100)
Tire Height (in) Tire Width (in)
 

Gear Calculator – Gear Ratio, Speed & Torque Estimator

The Gear Calculator is a powerful online tool that helps users calculate gear ratios, rotational speed (RPM), and torque between driving and driven gears. It’s widely used in mechanical engineering, automotive design, and cycling optimization.

What is a Gear Calculator?

A Gear Calculator determines how two or more gears interact in a mechanical system. By inputting values such as the number of teeth or rotational speed of one gear, the calculator computes the output speed or torque of the other.

Gear Ratio Formula

The basic formula for gear ratio is:

Gear Ratio = Number of Teeth on Driven Gear / Number of Teeth on Driving Gear

Other Key Formulas

  • Output RPM: Output RPM = Input RPM × (Driving Gear Teeth / Driven Gear Teeth)
  • Output Torque: Output Torque = Input Torque × (Driven Gear Teeth / Driving Gear Teeth)

Example Calculation

Given:

  • Driving Gear: 20 teeth
  • Driven Gear: 40 teeth
  • Input RPM: 1200

Gear Ratio = 40 / 20 = 2

Output RPM = 1200 × (20 / 40) = 600 RPM

How to Use the Gear Calculator

  1. Enter the number of teeth for the driving and driven gears
  2. Input the RPM or torque of the input gear
  3. Click “Calculate” to get the gear ratio, output RPM, and torque

Benefits of Using This Tool

  • Instant gear ratio and RPM calculations
  • Accurate results for engineers, hobbyists, and students
  • Useful for bikes, motors, gearboxes, and machinery
  • Simple interface, no login required

Applications

  • Mechanical Engineering
  • Automotive Gearbox Design
  • Cycling Gear Optimization
  • Industrial Equipment Maintenance

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FAQs About Gear Calculator

1. What is a gear ratio?

A gear ratio is the ratio of teeth between two meshing gears, indicating mechanical advantage or speed reduction.

2. How does gear ratio affect RPM?

The output RPM is inversely proportional to the gear ratio. A higher gear ratio reduces speed but increases torque.

3. Can this calculator handle compound gear trains?

This tool is designed for simple gear pairs, but you can calculate multiple stages manually.

4. Is it suitable for bicycles?

Yes, cyclists can use it to determine optimal front and rear sprocket configurations.

5. What units does the tool support?

You can use any consistent units for torque and RPM, as long as the gear teeth count is correctly inputted.