Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Gear Ratio Calculator

Determine the output speed and mechanical advantage of a gear pair by entering tooth counts, input RPM, and system efficiency. Ideal for engineers and hobbyists designing gearboxes, drivetrains, or robotics.

Driving Gear Teeth (teeth)

Driven Gear Teeth (teeth)

Input Speed (RPM)

System Efficiency (%)

Fill in the required fields to see your result.

Mechanical

Belt Drive Calculator

Calculate the driven pulley speed for a belt drive system by entering pulley diameters and the drive shaft RPM. Use it when sizing pulleys for motors, conveyor systems, or power tools.

Drive Pulley Diameter (inches)

Driven Pulley Diameter (inches)

Drive Speed (RPM)

Fill in the required fields to see your result.

Key differences

	Gear Ratio Calculator	Belt Drive Calculator
Category	Mechanical	Mechanical
Inputs required	4	3
Result	Output Speed (RPM)	Driven Speed (RPM)
What it does	Determine the output speed and mechanical advantage of a gear pair by entering tooth counts, input RPM, and system efficiency. Ideal for engineers and hobbyists designing gearboxes, drivetrains, or robotics.	Calculate the driven pulley speed for a belt drive system by entering pulley diameters and the drive shaft RPM. Use it when sizing pulleys for motors, conveyor systems, or power tools.