1. What is an RPM Calculator by Gear Ratio?

Definition: This calculator determines the output rotational speed (RPM) based on input RPM and gear ratio.

Purpose: It helps mechanical engineers, automotive technicians, and DIY enthusiasts calculate speed changes in gear systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( RPM_{out} \) — Output rotational speed (revolutions per minute)
• \( RPM_{in} \) — Input rotational speed (revolutions per minute)
• \( GR \) — Gear ratio (unitless)

Explanation: The output RPM decreases proportionally with increasing gear ratio (for reduction gears).

3. Importance of RPM Calculation

Details: Proper RPM calculation ensures correct speed matching between components, prevents equipment damage, and optimizes performance.

4. Using the Calculator

Tips: Enter the input RPM and gear ratio (default 1). For speed reduction, use GR > 1. For speed increase, use GR < 1. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical gear ratio range?
A: Common ratios range from 0.5 (speed increase) to 10+ (heavy reduction), depending on application.

Q2: How do I calculate gear ratio?
A: GR = Number of teeth on driven gear / Number of teeth on driving gear.

Q3: Does this work for belt and pulley systems?
A: Yes, use the pulley diameter ratio instead of tooth count.

Q4: What if I know the output RPM and need input RPM?
A: Rearrange the formula: RPM_in = RPM_out × GR.

Q5: How does multiple gear stages affect calculation?
A: Multiply individual gear ratios first, then apply to input RPM.