What Is Circularity Error?
Circularity error is the deviation between an analog stick's actual rotation path and a perfect circle, expressed as a percentage. When you rotate the stick at maximum deflection, an ideal controller would trace a smooth ring; real controllers trace a slightly rounded square. Stock PS5 and Xbox controllers average 6–9% — a deliberate engineering choice, not a defect.
What Circularity Error means
How Circularity Error Works
When you push an analog stick to its maximum deflection and slowly rotate it 360 degrees, the X and Y axis values trace a closed path. The test measures how that path compares to a perfect circle of radius 1.0. Three things shape the result: the physical gate (the plastic ring or octagon the stick can press against), the sensor's response curve, and any firmware calibration the manufacturer applies.
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Rotate the stick at maximum deflection
Push the thumbstick fully to the edge and slowly draw a complete 360-degree circle, pressing against the physical gate the entire time. The Gamepad API reports the X and Y axis values continuously — the path traced is the raw input the controller sends to the game.
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Compare the trace to a perfect unit circle
An ideal stick traces a circle of radius 1.0 — every point on the path is exactly the same distance from center. The circularity test samples hundreds of points along your trace and measures each point's distance from the unit circle's edge. The deviations get averaged.
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The result is expressed as a percentage
Average all the per-point deviations, divide by the unit circle's radius, and you get a percentage. A 0% result means every sampled point lay exactly on the perfect circle. A 10% result means the trace was, on average, 10% of the radius too close to or too far from the perfect circle's edge.
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Lower is not always better
A circularity error too close to zero means the stick is calibrated inside the unit-circle range — making max-input actions harder to trigger (Auto-Sprint, aerial rotation, full-speed running). Sony and Microsoft engineers deliberately set factory circularity at 6–9%, and controller modders tune to 7–9% as the practical sweet spot.
Circularity Error what your number means
Circularity error percentages have widely different interpretations depending on the controller type and the gate shape. The bands below reflect the practical experience of stock first-party controllers and after-market modders — not the marketing claims of controller brands.
| Circularity error % | Verdict | Meaning |
|---|---|---|
| 0–5% | Very low — possibly too low | Premium controllers with Hall-effect or TMR sticks, OR firmware-clipped budget controllers that report artificially low error. A trace this close to a perfect circle often means the stick can't reach max input — a real gameplay disadvantage in Rocket League aerials and Call of Duty auto-sprint. |
| 6–9% | Factory standard — ideal | The deliberate calibration target Sony and Microsoft use for stock DualSense and Xbox controllers. Battle Beaver and StickFix both tune modded controllers to this range as the practical sweet spot. Stick reaches max input reliably in all directions. |
| 10–15% | Above average | Older controllers, budget pads, or first-party controllers with light wear. Still usable for most games. May feel slightly imprecise in twin-stick games or fighting games where 8-direction input matters. |
| 20%+ | High — design or wear | Either a square-gate fighting pad (where the trace is physically a square — by design, not defect), OR a worn potentiometer controller with flat spots in specific directions. Run the test, then check for drift to distinguish the two. |
Stock PS5 and Xbox factory circularity averages 6–9% per Battle Beaver Customs' tuning data. A controller with 0–5% error often has firmware that clips inputs INSIDE the unit circle, reducing max-input reliability. The term 'error' is misleading — circularity is geometry, not failure.
Test for Circularity Error
Fix Circularity Error issues
Devices most affected by Circularity Error
Related glossary terms
Circularity Error questions
For stock PS5 and Xbox controllers, 6–9% is the factory target — and that's actually the practical sweet spot, not a problem to fix. Sony and Microsoft engineers deliberately chose this range because lower circularity errors can prevent the stick from reaching maximum input, which breaks max-input game mechanics like Auto-Sprint and aerial rotations. Professional controller modders like Battle Beaver Customs tune their recalibrated sticks to 7–9% specifically.
Because a stick calibrated to exactly trace the unit circle has no room to overshoot at maximum deflection — and many games require overshoot to register max-input actions. In Rocket League, you can't perform certain aerial rotations without the stick going slightly beyond the digital circle. In Call of Duty, Auto-Sprint may not trigger if the stick can't reach the threshold. The 'error' label is misleading — circularity describes geometry, not malfunction.
Software trickery, in some cases. Some controllers (GameSir is one named example per StickFix Repair's industry reporting) apply firmware-level clipping that constrains the reported analog values inside an artificially tight circle. The raw sensor data may produce normal circularity numbers, but the controller's microcontroller reshapes the output before exposing it to the Gamepad API. The result looks better on paper but performs worse in games that need real max-input range.
Sometimes — but the sensor type isn't the deciding factor. Hall-effect and TMR controllers can achieve cleaner traces because their sensors are inherently less noisy, but circularity is mostly determined by the physical gate shape, the calibration the manufacturer applies, and any post-processing in firmware. A well-calibrated potentiometer stick can produce identical circularity to a Hall-effect stick. A poorly-tuned Hall stick can produce worse circularity than a tuned potentiometer.
Some fighting game controllers (Hitbox arcade sticks, certain Hori fight pads, older arcade sticks) use a square or octagonal physical gate instead of a circular one. The stick physically cannot trace a circle because the gate stops it at corners — so the circularity test reports very high error (often 25–40%). This is a deliberate design choice for fighting games where 8-direction input must be unambiguous. Don't interpret high circularity error from a fighting pad as a defect.
Yes, on potentiometer-based controllers. As the carbon track wears unevenly, certain directions develop flat spots — areas where the resistance no longer changes smoothly. This creates dips in the circularity trace at specific angles. If you've used a controller for 300+ hours and the circularity number has increased significantly from when it was new, you're seeing early-stage potentiometer wear, often before stick drift becomes obvious at rest.
Probably not. 15% is above the 6–9% factory standard but well within the range of older, budget, or lightly-worn controllers. It may feel slightly imprecise in games that demand sub-degree stick accuracy (competitive twin-stick shooters, fighting games), but for most genres it's completely playable. If the number jumped from 8% to 15% on a previously-tested controller, that's wear worth tracking — but a single 15% reading on a controller you've never tested before isn't cause for replacement.
Further reading
- Circularity, Error Rate, And You: Battle Beaver's Tuning Methodology · Battle Beaver Customs · Retrieved