Conveyor Belt Pull & Drive Calculator — Straight, Incline, L, Z, Radius & S

Size the drive for a modular plastic belt conveyor from the layout you actually have: an infeed run, inclines, straight legs, and any number of turns for radius and S-conveyors. The calculator marches tension along the belt section by section, so a Z conveyor, a 90° radius belt, and a three-turn S path all use the same physics instead of a hand rule.

Enter the product as packages or bulk. Bulk on an incline steeper than a plain belt can hold turns into flight pockets, and the pocket capacity is sized from flight height, pitch, angle of repose, and loose density. Wear scenarios show how the pull grows as wearstrips age, and the result carries a curve edge-capacity screen, a corner speed ceiling, and a per-turn tension table.

The output is a running pull, a startup pull, and continuous and peak torque floors that the OneMotion auto-pick uses to name the smallest drum motor that passes at your belt width and speed. Every assumption the model leans on is listed in the sign-off summary.

How it works
  • Straight and incline runs: friction = μ × (belt + product weight per foot) × horizontal length; lift = weight × rise. The return path is split into slider and roller segments.
  • Turns: T_out = T_in · e^(μθ) + (μ · w · r_c / μ_rail)(e^(μθ) − 1), the exact curve solution, with a hand-method floor and a width-ratio ceiling around it.
  • Startup pull = running pull × static ratio + acceleration of the moving mass over the ramp time.
  • Service factors are additive (static nose bars, speed over 30 m/min, start-stop duty, bi-directional, elevation); peak torque floor = 1.25 × continuous.
  • Belt check: running pull against the belt's allowable working tension; in-curve tension against the derated curve capacity.
  • Drive check: vendor belt-pull rating at the belt width for drum motors, torque at the sprocket pitch radius for shaft drives, and RPM against the motor range.
  • Worked example, straight run: a 24 in belt weighing 2.4 lb/ft carrying 1 lb/ft of product over a 40 ft carryway at μ = 0.25 needs 0.25 × 3.4 × 40 = 34 lbf on the carryway plus 0.25 × 2.4 × 40 = 24 lbf on a slider-bed return — about 58 lbf running pull before service factors. At 60 ft/min that is 58 × 60 / 33,000 = 0.11 hp at the belt; startup adds the static friction ratio and the acceleration of the moving mass.

Free, no login. Your inputs are saved in this browser. Values are engineering references — verify against manufacturer data and applicable codes before a final design.

Built by the engineers behind Sanitary belt conveyors.

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Questions engineers ask

How is belt pull calculated for a radius or S-conveyor?
Each turn uses the exact curve solution, T_out = T_in × e^(μθ) plus a rail-drag term (μ × w × r_c / μ_rail)(e^(μθ) − 1), so tension compounds through every turn in sequence. Straight and incline runs add friction (μ × weight per foot × length) and lift (weight × rise). The result is the running pull at the drive, bracketed by a hand-method floor and a width-ratio ceiling.
What is startup pull and why is it higher than running pull?
Startup pull is the running pull multiplied by the static-to-kinetic friction ratio, plus the force to accelerate the moving belt and product mass over the ramp time. Drives are checked on both: continuous torque for running and peak torque for startup, with a peak floor of 1.25 times continuous.
How do I pick a drum motor from the belt pull?
The Torque & Motor card pulls the pulls, speed, and belt width from Belt Pull (or links to it), and its OneMotion auto-pick names the smallest series whose belt-pull rating at your belt width passes the continuous pull, the peak pull, and the RPM at your belt speed, and a manual drum or sprocket-driven shaft entry shows utilisation for each wear scenario.

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