Belt Pulley Speed & Center Distance Calculator

Calculate driven pulley RPM, speed reduction ratio, belt linear speed (FPM), and approximate belt pitch length for V-belt drives.

  • 100% free
  • Private in browser
  • No signup
  • No watermarks
Driven Shaft Speed (RPM)
875
Speed Reduction Ratio (D2/D1)
2
Estimated Belt Pitch Length (Inches)
55.1
Belt Surface Speed (Feet/Min FPM)
1,833

Rate this tool

Be the first to rate — helps others and improves this page.

About Belt Pulley Speed & Center Distance Calculator

Calculate driven pulley RPM, speed reduction ratio, belt linear speed (FPM), and approximate belt pitch length for V-belt drives. Enter Driver Pulley Diameter D1, Driven Pulley Diameter D2 and Driver Motor Speed and the tool works out Driven Shaft Speed, Speed Reduction Ratio and Estimated Belt Pitch Length straight away. Everything runs in your browser, so your data never leaves your device.

How to use Belt Pulley Speed & Center Distance Calculator

  1. Enter Driver Pulley Diameter D1, Driven Pulley Diameter D2 and Driver Motor Speed.
  2. Adjust the remaining options (Center Distance Between Shafts) to match your case.
  3. Read Driven Shaft Speed, Speed Reduction Ratio and Estimated Belt Pitch Length in the results panel — copy or download what you need.

Key features

  • Shows Driven Shaft Speed (RPM)
  • Shows Speed Reduction Ratio (D2/D1)
  • Shows Estimated Belt Pitch Length (Inches)
  • 4 adjustable inputs, results update as you type
  • No signup, no limits

Frequently asked questions

Is this calculation free and private?
Yes, 100% of calculations execute locally in your web browser. No inputs or personal data are stored or transmitted.
What does the Belt Pulley Speed & Center Distance Calculator give me?
It works out Driven Shaft Speed, Speed Reduction Ratio, Estimated Belt Pitch Length and Belt Surface Speed, updating live as you change the inputs.
What do I need to enter?
Just Driver Pulley Diameter D1, Driven Pulley Diameter D2, Driver Motor Speed and Center Distance Between Shafts. Every field has a sensible default you can start from.
Is my data uploaded anywhere?
No. The calculation runs in your browser with JavaScript — nothing you type is sent to a server or stored.
Does it work on a phone?
Yes. The layout adapts to small screens and needs no app or signup.

Related In-Depth Guides

Learn practical workflows, real-world examples, and expert tips in our comprehensive guides:

Engineering & 3D Printing · 5 min read

How to Calibrate Steps Per MM for 3D Printers & CNC Machines: Belts vs Lead Screws

Eliminate dimensional inaccuracies in 3D printing and CNC milling. Calculate exact steps-per-mm, microstepping rates, and belt pulley speed ratios.