Circularity Error Test

No Controller

Left Stick

AXIS 00.00000
AXIS 10.00000
Avg Error:0.0%
0 Points

Right Stick

AXIS 20.00000
AXIS 30.00000
Avg Error:0.0%
0 Points
ControllerTest.io Benchmark
Circularity Test

Test Instructions

Slowly rotate the stick along the edge to draw a circle. Move slowly so each point can be captured. Avg Error = average deviation from perfect circle (100% magnitude).

Rotate sticks to begin tracing

What is Stick Circularity?

Understanding how analog stick accuracy affects your gaming precision

Perfect Circularity

When you rotate your joystick in a full circle at maximum deflection, an ideal controller should produce a perfect circle of coordinates. This indicates precise mechanical alignment and accurate sensor readings across all angles.

Circularity Errors

Deviations from perfect circularity show as bumps, flat spots, or irregular shapes. These errors can cause inconsistent aiming in FPS games, uneven turning in racing games, and unpredictable movement in platformers.

Test Methodology

How the Test Works

Our circularity test measures the deviation from a perfect unit circle as you rotate the joystick around its full range of motion.

  • Under 5% Error

    Excellent precision suitable for competitive gaming and precision aiming

  • 5-10% Error

    Good quality typical of most consumer controllers

  • Over 15% Error

    May cause noticeable accuracy issues in gameplay

Edge-to-edge trace analysis

Frequently Asked Questions

Common questions about joystick circularity testing

Q Why does my controller have flat spots?

Flat spots in the circularity trace are often caused by mechanical limitations in the potentiometer design or physical wear on the controller's internal components. Hall-effect sticks typically show better roundness.

Q What are quadrant errors?

Quadrant errors show how accuracy varies across different directions (Right, Up, Left, Down). Uneven quadrant scores may indicate mechanical issues or worn potentiometers in specific directions.

Q How do I get accurate results?

Push the joystick fully to the edge and rotate slowly and steadily. Cover all 360° at least twice for best accuracy. Make sure to push all the way to the mechanical limit.

Q Can poor circularity be fixed?

Minor circularity issues can sometimes be compensated with in-game sensitivity curves. Severe issues typically require replacing the analog stick module or the entire controller.