Gear Ratio Calculator
Calculate gear ratio from input and output teeth
About this calculator
A gear ratio calculator determines the mechanical advantage between two gears by comparing the number of teeth on the input (driving) gear to the output (driven) gear. This tool is essential for engineers, mechanics, and hobbyists working with transmissions, bicycles, machinery, or any mechanical system requiring precise speed and torque calculations. Understanding gear ratios helps optimize performance, determine speed reduction or multiplication, and calculate the mechanical advantage in various applications.
How to use
Enter the number of teeth on the input gear (the driving gear) in the first field. Then enter the number of teeth on the output gear (the driven gear) in the second field. The calculator will instantly display the gear ratio, showing how many times the input gear must turn for one complete rotation of the output gear.
Frequently asked questions
What does a 3:1 gear ratio mean?
A 3:1 ratio means the input gear rotates three times for every one rotation of the output gear, providing speed reduction and increased torque.
How do I calculate gear ratio manually?
Divide the number of teeth on the output gear by the number of teeth on the input gear: Gear Ratio = Output Teeth ÷ Input Teeth.
What's the difference between gear ratio and gear reduction?
Gear ratio is the mathematical relationship between gears, while gear reduction specifically refers to ratios greater than 1:1 that reduce speed and increase torque.