Conveyor Speed Calculator
Calculate conveyor belt linear speed (FPM, ft/s, m/min, m/s), head pulley RPM, required gearbox ratio, package throughput (items/hr), transit time, and motor horsepower. Edit drivetrain parameters or enter a target FPM directly to reverse-calculate the required gear reduction.
1. Motor, Gearbox, Pulley & Load Controls
2. Belt Speed, Throughput & Motor Power Results
3. VFD Frequency Speed Curve & Throughput Schedule
Comparison of conveyor belt speed, hourly throughput, and required drive power across Variable Frequency Drive (VFD) operating frequencies for your configured 25.00:1 total ratio & 6.00 in pulley:
| VFD Frequency | Motor / Pulley RPM | Belt Speed (FPM / m/s) | Throughput (Items/hr) | Transit Time | Req. Motor HP |
|---|---|---|---|---|---|
| 20 Hz (33% Speed) | 583 / 23.3 RPM | 36.7 FPM (0.19 m/s) | 1,100 / hr | 81.9 sec | 0.34 HP |
| 30 Hz (50% Speed) | 875 / 35.0 RPM | 55.0 FPM (0.28 m/s) | 1,649 / hr | 54.6 sec | 0.51 HP |
| 45 Hz (75% Speed) | 1,313 / 52.5 RPM | 82.5 FPM (0.42 m/s) | 2,474 / hr | 36.4 sec | 0.76 HP |
| 60 Hz (100% Nominal) | 1,750 / 70.0 RPM | 110.0 FPM (0.56 m/s) | 3,299 / hr | 27.3 sec | 1.01 HP |
| 70 Hz (117% Speed) | 2,042 / 81.7 RPM | 128.3 FPM (0.65 m/s) | 3,848 / hr | 23.4 sec | 1.18 HP |
| 75 Hz (125% Boost) | 2,188 / 87.5 RPM | 137.4 FPM (0.70 m/s) | 4,123 / hr | 21.8 sec | 1.27 HP |
Conveyor Speed & Drive Power Formulas
Linear conveyor velocity and drive power follow standard CEMA and mechanical power-transmission kinematics:
N_pulley = N_motor ÷ (Gear_Ratio × Sprocket_Ratio)
D_eff (in) = Pulley_Dia_in + Belt_Thickness_in
Belt Speed (FPM) = (π × D_eff × N_pulley) ÷ 12
Throughput (items/hr) = (FPM × 12 ÷ Pitch_in) × 60
Belt Pull (lbf) = 1.15 × Live_Load × (μ·cosθ + sinθ)
Motor HP = (Belt_Pull × FPM) ÷ (33,000 × 0.85)
Constants: 1 HP = 33,000 ft·lbf/min; 1.15 accounts for belt and return-idler deadweight; 0.85 represents typical gearmotor drivetrain efficiency.
Illustrative Example & How to Use
Illustrative Example (1,750 RPM Motor @ 60 Hz, 25:1 Gearbox, 6.0 in Pulley, 50 ft Length, 24 in Pitch, 30 lb Box):
Belt Speed = (π × 6.0 × 70.0) ÷ 12 = 110.0 FPM (1.83 ft/s)
Throughput = (109.96 × 12 ÷ 24) × 60 = 3,299 items/hr
Motor HP = (258.75 lbf × 109.96) ÷ (33,000 × 0.85) = 1.01 HP
How to Use: Enter your motor RPM, VFD frequency, gearbox ratio, and drive pulley diameter to compute FPM—or type a desired Target Belt Speed (FPM) to automatically solve for the required gearbox ratio. Click Reset Defaults to restore the warehouse baseline.
Frequently Asked Questions
How do you calculate conveyor belt speed in feet per minute (FPM)?
Multiply Pi (3.14159) by the effective drive pulley diameter in inches and the head pulley rotational speed in RPM, then divide by 12 inches per foot: Belt Speed (FPM) = (π × D_eff × Pulley_RPM) ÷ 12. For a 6-inch pulley turning at 70 RPM, belt speed is 110.0 FPM.
How do you find head pulley RPM from motor RPM and gearbox ratio?
Divide the effective motor speed (adjusted for VFD frequency) by the product of the gearbox reduction ratio and any secondary chain or timing-belt sprocket ratio: Pulley_RPM = Motor_RPM ÷ (Gearbox_Ratio × Secondary_Ratio).
How does belt thickness affect conveyor speed calculations?
When a belt wraps around the head pulley, its neutral pitch line travels along the centerline of the belt thickness rather than the bare metal drum surface. Adding the belt thickness to the pulley diameter (D_eff = Pulley_Dia + Belt_Thickness) accounts for this larger radius, which increases linear belt speed by 2% to 5% on small pulleys.
How do you calculate required conveyor drive motor horsepower (HP)?
Multiply the total effective belt pull (in pounds-force, accounting for sliding/rolling friction and any incline lift) by the belt speed in FPM, divide by 33,000 ft·lbf/min per horsepower, and divide by the mechanical drivetrain efficiency (typically 0.85): Motor_HP = (Belt_Pull_lbf × FPM) ÷ (33,000 × 0.85).