Mouse DPI Test — Measure Your Mouse's Real DPI With a Ruler
DPI (more precisely CPI, counts per inch) is how many position steps your mouse reports per inch of movement. This page estimates it from real mouse movement: you move the mouse a measured distance while the page counts the steps it receives, then divides one by the other.
Quick answer: Put a ruler on the mousepad, press Start, then drag the mouse exactly 2 inches (or 5 cm) along the ruler at a steady speed and press Stop. The page shows the counted steps and the estimated DPI. Turn off pointer acceleration first, or the number comes out too high.
- Turn off pointer acceleration (Windows: “Enhance pointer precision”; macOS: mouse acceleration).
- Lay a ruler next to the mouse. Note where the mouse starts.
- Press Start, drag the mouse 2 inches straight along the ruler, then Stop.
- Repeat three times — we show the median, and the spread tells you how trustworthy it is.
| Method | Counts of pointer movement over a measured distance: DPI ≈ steps ÷ inches |
|---|---|
| Accuracy | Good with pointer acceleration off and a steady drag; rough otherwise |
| Before you start | Turn off 'Enhance pointer precision' (Windows) or mouse acceleration (macOS) |
| What it is for | Feeding the eDPI calculator with a realistic DPI instead of a nameplate value |
Why the result is an estimate, not a lab measurement
The page only sees movement events after the operating system and browser have processed them. If pointer acceleration is on, slow and fast drags produce different numbers; if the drag wanders off the ruler line, the distance is wrong. For a reliable reading: disable acceleration, drag along a long straight distance (2 inches or 5 cm or more), steady pace, and repeat three times — the median of three runs is usually within a few percent of the real DPI.
What to do with the number
Use it in the eDPI calculator to compare sensitivity across games, or to reproduce the exact feel of an old mouse on a new one. Most games only care about DPI × in-game sensitivity, so as long as both numbers are consistent, your aim stays the same even if DPI changes.
When to use this test
- Your mouse has a DPI button but no display and you want to know which setting you are on
- You are computing eDPI for a game and want the actual DPI rather than the marketing number
- You want to verify that a replacement mouse matches the old one's feel
- You are checking whether a mouse keeps its DPI setting after being unplugged