1. What is a Pulley To Pulley Calculator?

Definition: This calculator determines the output RPM of a driven pulley based on the input RPM and the diameters of both pulleys.

Purpose: It helps mechanical engineers, technicians, and DIYers design and troubleshoot belt-driven systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( RPM2 \) — Output RPM of driven pulley
• \( RPM1 \) — Input RPM of drive pulley
• \( D1 \) — Diameter of drive pulley (inches)
• \( D2 \) — Diameter of driven pulley (inches)

Explanation: The speed ratio between pulleys is inversely proportional to their diameter ratio.

3. Importance of Pulley Calculations

Details: Proper pulley sizing ensures optimal power transmission, prevents belt slippage, and maintains desired machine speeds.

4. Using the Calculator

Tips: Enter the input RPM, drive pulley diameter, and driven pulley diameter. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What if I know the pulley ratio instead of diameters?
A: Simply enter 1 for D1 and your ratio value for D2 (e.g., for 2:1 ratio, D1=1, D2=2).

Q2: Does belt thickness affect the calculation?
A: For precision, measure pulley diameter at the belt's pitch line, but for most applications, outer diameter is sufficient.

Q3: Can I use this for multiple pulley systems?
A: Yes, calculate sequentially from driver to final driven pulley.

Q4: What about belt length calculations?
A: This calculator only determines RPM. Use our Belt Length Calculator for that purpose.

Q5: How accurate is this calculation?
A: It's theoretically perfect for ideal systems. Real-world factors like belt slip may cause minor variations.