PPR (pulses per revolution) is the number of electrical pulses an encoder produces per full shaft rotation. A 1000 PPR encoder generates 1000 pulses per revolution in single-ended mode and 4000 counts per revolution in quadrature (4×) mode.

What is quadrature encoding?

Quadrature (AB) encoders output two signals 90° apart. By counting all four edges (rising and falling) of both channels, the controller gets 4× the native PPR — better resolution and direction sensing with no extra hardware cost.

How is max RPM calculated?

Max RPM = (Sampling Rate × 60) ÷ (PPR × Quadrature Factor). The sampling rate must be at least 2× the pulse frequency (Nyquist). This tool uses the 4× quadrature count as the worst case to give a conservative limit.

What does position resolution mean for a linear axis?

Position resolution is the smallest movement the system can detect. It equals the leadscrew or belt pitch (mm per revolution) divided by the quadrature count. For example, 5 mm pitch ÷ 4000 counts = 0.00125 mm (1.25 µm) per count.

Does this work for linear encoders?

Yes. Enter the linear pitch (the distance the axis travels per encoder revolution) in the pitch field. The calculator outputs mm per count and µm per count for both 1× and 4× modes.

Encoder Resolution Calculator

Name: Encoder Resolution Calculator
Availability: InStock
Author: Nham Vu

Calculate angular resolution, position resolution, max RPM, and quadrature counts for rotary and linear encoders.

Encoder Parameters

PPR — Pulses per Revolution

Native pulses from the encoder datasheet.

Linear Pitch (mm/rev) — optional

Leadscrew or belt pitch for linear axes. Leave blank for rotary only.

Controller Sampling Rate (Hz) — optional

Pulse counting rate of your controller or DSP. Used to compute max RPM.

Rotary Resolution

—

°/count (1×)

—

°/count (4× quad)

—

counts/rev (1×)

—

counts/rev (4× quad)

Full Summary

Parameter	1× (single-ended)	4× (quadrature)

Enter PPR above and click Calculate to see results.

Summary

Calculate angular resolution, position resolution, max RPM, and quadrature counts for rotary and linear encoders.

How it works

Enter the encoder PPR (pulses per revolution) for rotary calculations.
For linear encoders, enter the pitch (mm per revolution) to get mm per count.
Input your controller sampling rate (Hz) to find the maximum safe RPM.
Quadrature count (4× PPR) is computed automatically for AB encoder setups.
All results update instantly as you type.

Use cases

Size an encoder for a CNC axis to meet a target position resolution in microns.
Check whether a servo controller sampling rate is fast enough for a given RPM.
Compare single-ended vs quadrature mode count resolution before ordering hardware.
Verify angular resolution for a robotic joint against motion-profile requirements.
Convert manufacturer PPR spec to degrees per count for control-loop tuning.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu