Encoder resolution determines the smallest angle a rotary encoder can detect. Incremental encoders use PPR (Pulses Per Revolution), while absolute encoders use bit count. Quadrature decoding multiplies incremental encoder resolution by 4 using both edges of both channels.
Incremental Encoder
Absolute Encoder
Resolution by Application
How to Use the Encoder Resolution Calculator
This encoder resolution calculator converts PPR (incremental) or bit count (absolute) to angular resolution in degrees per count. Select quadrature decoding mode for incremental encoders to see the 4× resolution benefit.
Incremental Encoder Resolution
Resolution (°/count) = 360 / (PPR × decode_multiplier). A 1000 PPR encoder at 1× = 0.36°. Same encoder at 4× quadrature = 0.09°. 4× quadrature uses both rising and falling edges of both A and B channels, giving 4 counts per physical pulse period. Most microcontroller timers support 4× mode directly.
Absolute Encoder Resolution
Resolution (°/count) = 360 / 2^bits. 8-bit: 360/256 = 1.406°. 12-bit: 360/4096 = 0.088°. 16-bit: 0.0055°. An absolute encoder never loses position on power-down, making it ideal for CNC machines, robotic joints, and antenna rotators. Incremental encoders require homing on startup.
Choosing Encoder Resolution
Hobby servo control: 12-bit (4096 positions) is sufficient. CNC stepper system: match encoder CPR to stepper microsteps. If a stepper moves 1.8° and uses 16 microsteps, it moves 0.1125° per step — use an encoder with better than 0.1° resolution. Industrial servo systems use 17–24-bit encoders for sub-arcsecond positioning.
FAQ
Is this encoder resolution calculator free?
Yes, completely free. Calculate encoder resolution for any PPR or bit count without any account or payment.
Is my data private?
All calculations run in your browser. No data is sent to any server.
What is an incremental encoder and what is PPR?
An incremental encoder outputs pulses as the shaft rotates. PPR (Pulses Per Revolution) is the number of output pulses per full rotation. A 1000 PPR encoder produces 1000 pulses per 360° revolution. Angular resolution = 360° / PPR = 0.36° per count.
What is a quadrature encoder and how does it affect resolution?
A quadrature encoder has two output channels (A and B) offset by 90°. By counting rising and falling edges of both channels (4× decoding), resolution is multiplied by 4. A 1000 PPR encoder in quadrature mode = 4000 counts per revolution = 0.09° resolution.
What is an absolute encoder?
An absolute encoder provides a unique binary code for every shaft position. An 8-bit encoder = 256 unique positions per revolution = 360°/256 = 1.406° resolution. A 12-bit encoder = 4096 positions = 0.088° resolution. No reference point or homing required.
What resolution do I need for my application?
Robotics/CNC: 0.01–0.1° (1000–36000 counts/rev). Industrial servo: 0.001–0.01° (360,000+ counts). Consumer electronics/motor control: 0.1–1°. Dial or selector positions: 12–360 positions (1°–30°). Use the next higher standard value available.
What is the difference between CPR and PPR?
PPR (Pulses Per Revolution) refers to single-channel pulses. CPR (Counts Per Revolution) often refers to the quadrature count (4× PPR). Check whether your encoder datasheet uses PPR or CPR — they may differ by 4×, which significantly affects your resolution calculation.