Data notes · October 12, 2026
Real vs advertised mouse DPI
The DPI number in your mouse software is a request, not a measurement. Sensors have manufacturing tolerances, firmware rounds counts, and some mice interpolate at certain steps — so the DPI your driver claims and the DPI your sensor actually reports are often different. Deviations of a few percent are normal; large ones silently break every sensitivity calculation you've ever copied.
The fix takes five minutes with our browser-based tester — no drivers, nothing installed, and the counts never leave your machine.
The 5-minute test
- 1. Open the DPI tester and enter the DPI your software claims.
- 2. Set a physical distance — two credit cards side by side are exactly 17.1 cm if you don't have a ruler.
- 3. Click start, move the mouse in one smooth straight line for that exact distance, then finish.
- 4. Run it three times and average. Smooth motion matters — hesitations add false counts.
Reading the result
Within 2–3% of claimed: normal sensor tolerance — change nothing. 3–8% off: your cm/360 is drifting from every calculator's prediction; decide whether precision matters enough to correct the software setting. Over 8%: something is wrong — check for driver interpolation, a DPI step the sensor doesn't natively support, or a dirty lens.
Why this matters for conversions
Every sensitivity conversion assumes your DPI is true. If your mouse reports 790 counts per inch when set to 800, your "exact" 40.8 cm/360 is really 41.3 — small, but it compounds across every game you play. Measuring once takes five minutes and makes every other number on this site personally accurate.
Help build the dataset
We're collecting community test results (mouse model + measured DPI) to publish per-model accuracy data. Email your result to corrections@senslib.com — with enough submissions, the per-model table becomes another thing competitors can't fake.