Gear Ratio Speed Calculator
Calculate gear ratios, speed changes, and mechanical advantage in gear systems
Calculate Gear Ratio and Speed
Number of teeth on the driving (input) gear
Number of teeth on the driven (output) gear
Rotational speed of the input gear
Output teeth ÷ Input teeth
Calculation Results
System Type:
Torque Multiplication: 0.000×
Formula: Output Speed = Input Speed ÷ Gear Ratio
Speed Formula: 0 ÷ 0.000 = 0.0 rpm
Gear System Analysis
Example Calculation
Electric Motor with Gearbox
Input Gear (Motor): 20 teeth
Output Gear (Driven): 60 teeth
Motor Speed: 1800 RPM
Gear Ratio: 60 ÷ 20 = 3:1
Calculation
Output Speed = Input Speed ÷ Gear Ratio
Output Speed = 1800 RPM ÷ 3
Output Speed = 600 RPM
Torque Increase = 3× (theoretical)
Common Gear Systems
Speed Reduction
Large output gear, small input gear
Increases torque, decreases speed
Speed Increase
Small output gear, large input gear
Increases speed, decreases torque
Direct Drive
Equal gear sizes (1:1 ratio)
Speed and torque unchanged
Gear System Tips
Gear ratio = Output teeth ÷ Input teeth
Speed ratio equals gear ratio
Higher gear ratio = more torque, less speed
Lower gear ratio = more speed, less torque
Consider efficiency losses in real applications
Understanding Gear Ratios and Speed
What is a Gear Ratio?
The gear ratio is the relationship between the number of teeth on two interconnected gears. It determines how rotational speed and torque are transferred from the input (driving) gear to the output (driven) gear.
How Speed Changes
- •If the output gear has more teeth than the input gear, it rotates slower
- •If the output gear has fewer teeth than the input gear, it rotates faster
- •The speed ratio is inversely proportional to the gear ratio
Mathematical Relationships
Gear Ratio = Output Teeth ÷ Input Teeth
Speed Ratio = Input Speed ÷ Output Speed
Output Speed = Input Speed ÷ Gear Ratio
Torque Multiplication = Gear Ratio
Note: In real applications, consider efficiency losses due to friction, typically 2-5% per gear mesh.