Conveyor Calculations for Proper Design

Conveyor belt systems are used by a variety of industries to assist in transporting, assembling, packaging, and more. Conveyors relieve staff from dangerous lifting tasks and expedite productivity. Because conveyor systems are so critical to the safety and efficacy of fabrication shops, conveyor calculations for proper design are necessary to prevent overloading your system. Redline Systems Inc delves into which measurements to acquire when assessing your equipment and the equations needed to achieve those calculations.

Conveyor Calculations Legend

To make sense of each conveyor calculation, we’ve compiled a comprehensive legend for reference.

B: Sine of angle of incline C: Center to center distance (inches) D: Diameter of drive pulley

d: Diameter of tail pulley E: Effective Tension (lbs.) E1: Slack side tension (lbs.)

E2: Tight side tension (lbs.) F: Coefficient of friction G1: Load per square ft. (lbs.)

G2: Load per hours (lbs.) HP: Horsepower K: Drive factor

L: Belt length (inches) M: Overall belt weight P: Product weight (lbs.)

RPM: Revolutions per minute S: Conveyor speed (feet per minute) T: Operating tension PIW (lbs.)

W: Belt weight

Different Calculations to Acquire

Belt Speed

Expressed in feet per minute, or FPM, you’ll find the accurate belt speed using the following equation.

S = D x RPM x .2618 x 1.021

Belt Length

Avoid coming up short or having a belt that extends beyond use by using calculations based on the conveyor’s pulleys.

  • When the head and tail pulley are the same size: L = (D + d)/2 x 3.1416 + 2C
  • When one pulley is larger than the other: L = (D + d)/2 x 3.1416 + 2C + (D – d)^2 / 4C

Belt Load

Gather the proper belt load calculation to prevent putting too much pressure on your conveyor setup.

  • When the load is per square foot: P = G1 x C (in feet) x W (in feet)
  • When the load is pounds per hour: P = G2 / (S x 60) x C (in feet)


Level conveyors: HP = F x S x (P + M) / 33,000

Inclined conveyors: HP = ((P x B) + (P + M) x F X S) / 33,000

Effective Tension

Effective tension is the pull need to move the belt and load horizontally and is measured by the following.

E = F x (P + M)

Slack Side Tension

Any additional tension to prevent slippage is represented by E1 = E x K

Tight Side Tension

The total tension needed to move the belt and load horizontally is expressed by E2 = E + E1

Operating Tension

Operating tension determines the working strength of the belt on a per inch of width basis. T = E2 / W

Once you gather all the necessary conveyor calculations for proper design, you’re ready to create your custom system. At Redline Systems Inc, our complete conveyor product line includes portable conveyor belts for projects that take the road and customizable systems to meet every fabrication project’s needs. With over 40 years of industrial experience, you’re guaranteed satisfactory service.