A conveyor usually consists of a rubber belt, serving as a platform, which is free to rotate around a series of separated rollers. Objects and materials placed on top of the conveyor belt will be moved from one edge to the other as the rollers spin. Grocery stores use them to move customers' items down the checkout lane to the barcode scanner, while athletes use them in the form of treadmills to simulate running while not actually moving relative to the ground. The speed at which the conveyor belt moves is dependent on the diameter of the rollers and the rotation rate.

Measure the diameter of the rollers around which the conveyor belt is wrapped.

Multiply the diameter of the roller by pi (3.14159). This calculation will yield the circumference of the rollers. Every time the roller spins one revolution, the conveyor will be moved a linear distance equivalent to the circumference of the roller. Pi is a dimensionless factor, meaning it does not matter whether inches, centimetres or any other units of measurement are used.

Measure the revolutions per minute (RPM) of the rollers. Count how many full revolutions (rotations) are made by the roller in one minute.

Multiply the RPM by the circumference of the roller. This calculation will give the linear distance traversed by a point on the conveyor belt in one minute.

#### Warning

When making measurements, keep fingers away from the rollers. They can pull your fingers in quickly and smash them between the conveyor belt and cause severe injury.

#### Tips and warnings

- Distance travelled (displacement) per a change in time is the definition of velocity (speed).
- To convert the speed of the conveyor belt from inches per minute to miles per hour:
- Multiply by 60 to convert to inches per hour.
- Divide by 12, then divide by 5280, to convert to miles per hour (12 inches = 1 foot, 5280 feet = 1 mile).
- When making measurements, keep fingers away from the rollers. They can pull your fingers in quickly and smash them between the conveyor belt and cause severe injury.