400 DPI Test — Verify Your Mouse DPI Online
The 400 DPI test verifies whether your mouse is actually tracking at 400 Dots Per Inch — the most widely used DPI setting among professional FPS players worldwide. DPI accuracy matters here because 400 DPI is specifically chosen to reduce hand jitter: at 400 DPI, your cursor moves only 400 pixels per inch of physical mouse movement, forcing deliberate, controlled wrist motions that produce more consistent crosshair placement in games like CS2, Valorant, and Apex Legends. According to pro settings databases, approximately 40–50% of professional CS2 players use between 400 and 800 DPI, with many legends of the game — including s1mple at peak performance — running exactly 400 DPI. At this sensitivity, most players use a mousepad of 45 cm or larger to accommodate the bigger wrist movements required. Real-world testing by RTINGS and similar labs shows gaming mice can deviate ±3–8% from their rated DPI — meaning your "400 DPI" setting might actually be running at 368–432 DPI. A verified 400 DPI reading confirms your eDPI calculation is grounded in fact, not assumption. This free browser test uses a physical ruler measurement to determine your mouse's actual DPI without any software installation.
Choose Your DPI Context
Each variant calibrates the benchmark table and guide content to a specific DPI use case.
DPI Checker
Move your mouse across a ruler to measure its actual DPI
How far will you move your mouse? (use a ruler)
🖱️
Grab a ruler, then click Start
Move your mouse exactly 2" across a ruler, then click or press Space to stop.
Gaming Mouse DPI Reference
| DPI Range | Rating | Best For |
|---|---|---|
| < 400 | Very Low 🐢 | FPS sniping; large mousepads |
| 400–800 | Low ✅ (Pro) | Competitive FPS (CS2, Valorant pros) |
| 800–1600 | Medium ⚡ | All-round gaming, desktop use |
| 1600–3200 | High 🏃 | MOBA, 4K monitors, casual gaming |
| 3200+ | Very High 🚀 | Desktop productivity; reduce in-game |
Is 400 DPI Good for Gaming?
These benchmarks are calibrated for the 400 DPI use case. Compare your measured DPI result against these tiers to evaluate your setup.
| DPI Range | Rating |
|---|---|
| 380–420 DPI | Accurate |
| 360–380 DPI | Acceptable |
| 420–440 DPI | Acceptable |
| < 360 DPI | Drifted Low |
| > 440 DPI | Drifted High |
Source: Aggregated from pro settings databases, RTINGS sensor testing, and gaming community data. Benchmarks are specific to the 400 DPI context.
Frequently Asked Questions
Why do so many pro gamers use 400 DPI?
Professional FPS players use 400 DPI because low DPI eliminates micro-tremors — tiny involuntary hand movements that would cause significant cursor deviation at high DPI. At 400 DPI, the same small hand tremor moves the cursor far fewer pixels than at 800 or 1,600 DPI, effectively filtering it out. This makes crosshair placement more consistent and repeatable, which is critical for headshot accuracy in games like CS2. The tradeoff is that players must use a large mousepad and sweep their full arm for 180° turns.
Is 400 DPI good for all games?
400 DPI is specifically well-suited for precision FPS games (CS2, Valorant, Apex) where individual pixel accuracy is critical. For MOBA games like League of Legends or Dota 2, 400 DPI is often uncomfortably slow — the cursor struggles to cross large minimaps and manage multiple screen elements quickly. For battle royale games, 400 DPI is functional but many players prefer 800 DPI as a more versatile starting point. For desktop use, 400 DPI requires significant mouse movement to traverse a screen, making everyday computer work tiring.
What in-game sensitivity should I use with 400 DPI?
Your target eDPI (effective DPI) guides this decision. At 400 hardware DPI: for CS2, a typical pro eDPI of 800–1,200 means setting in-game sensitivity to 2.0–3.0. For Valorant, pros average 200–400 eDPI, meaning a sensitivity of 0.5–1.0 at 400 DPI. For Apex Legends, 1,200–1,600 eDPI is common, meaning sensitivity 3.0–4.0 at 400 DPI. Use an eDPI calculator to find the exact in-game sensitivity that matches your target eDPI once you've confirmed your hardware DPI with this tool.
My mouse DPI test shows 380 DPI instead of 400 — is that a problem?
A reading of 380 DPI (5% below rated) is within the normal tolerance range for gaming mouse sensors and is not a problem for gameplay. Most gaming mice have sensors accurate to ±3–8% of their rated DPI. To improve accuracy: repeat the test 3 times and average the results, use a rigid ruler rather than a flexible tape measure, move your mouse in a perfectly straight horizontal line, and ensure Windows 'Enhance Pointer Precision' (mouse acceleration) is turned off before testing.
Does my mousepad affect DPI checker results?
Yes, significantly. Optical sensors read their tracking surface — a slippery, reflective, or very dark mousepad can cause the sensor to mistrack and produce inaccurate DPI readings. For the most accurate test: use your regular gaming mousepad, ensure it is clean and flat, and test at your normal mouse movement speed. Avoid testing on glass, bare metal, or glossy surfaces. Testing on an inconsistent surface can skew DPI readings by 10–20% compared to a proper mousepad.
What mousepad size do I need for 400 DPI gaming?
At 400 DPI, a 360° horizontal turn in CS2 (at standard sensitivity) requires approximately 45–60 cm of physical mouse movement. To avoid running out of space during rapid in-game turns, most 400 DPI gamers use an extended or XXL mousepad — typically 450 mm × 400 mm or larger. Popular choices include the SteelSeries QcK XL, Logitech G840, and Razer Gigantus V2 XXL. This large physical travel is one of the main reasons some players prefer 800 DPI instead.
Last updated: