What This Calculator Adds Up
"Input lag" isn't one single number - it's the sum of several separate delays that happen between the moment you physically click or press a key and the moment the resulting frame is actually visible on your screen. No spec sheet gives you the combined total, because it depends on your specific frame rate, peripherals, and display together. This calculator adds the real, distinct stages so you get one honest estimate for your exact setup.
How to Use This Calculator
- Enter your in-game frame rate (this is converted into frame time automatically).
- Enter your peripheral lag - many gaming mice and keyboards report this figure, or it's roughly under 2ms for a modern wired device polling at 1000Hz.
- Enter your display's processing lag, usually listed in its review or spec sheet as "input lag" at your chosen refresh rate.
- Enter your panel's pixel response time (gray-to-gray), also found in most monitor reviews.
- Your total estimated system latency updates instantly.
How the Calculation Works
Frame Time (ms) = 1000 ÷ FPS
Total Lag = Peripheral Lag + Frame Time + Display Processing Lag + Pixel Response
Frame time represents how long the game engine takes to produce and queue each frame at your current FPS - a major and often underestimated contributor, since it scales inversely with frame rate. The other three stages are comparatively small and fixed by your specific hardware.
Understanding Each Stage
| Stage | What It Represents |
|---|---|
| Peripheral Lag | Time from physical press to the signal reaching your PC (USB polling + internal processing) |
| Frame Time | Time your game engine takes to render and present one frame at your current FPS |
| Display Processing | Time your monitor's internal scaler/processor takes before showing the signal |
| Pixel Response | Time individual pixels take to physically change color (gray-to-gray) |
Benefits and Practical Uses
- Understand where your setup's real latency actually comes from before spending on new hardware.
- See exactly how much raising your frame rate reduces total lag compared to a faster monitor alone.
- Compare two hypothetical setups (e.g. 60fps vs 144fps) side by side using the same formula.
Common Mistakes to Avoid
- Ignoring frame rate's outsized impact - going from 60fps to 144fps cuts roughly 9.8ms off your frame time alone, often a bigger win than any single hardware upgrade.
- Assuming a monitor's advertised response time equals total lag - pixel response is only one of four stages, and display processing lag is frequently the larger of the two on that side.
Frequently Asked Questions
What's a "good" total input lag for competitive gaming?
There's no universal threshold, but many competitive setups aim to keep total estimated system latency under roughly 20-25ms by combining a high frame rate with a low-lag display and responsive peripherals.
Does V-Sync affect this calculation?
Yes, significantly - V-Sync and frame-rate caps can add substantial queued frame delay beyond simple frame time, which this calculator doesn't model since it varies heavily by implementation. Disabling V-Sync generally keeps actual lag closer to this estimate.
Where do I find my monitor's processing lag and pixel response numbers?
Independent monitor review sites that test with dedicated latency hardware are the most reliable source - manufacturer spec sheets sometimes list only the more flattering of the two numbers.
Conclusion
Total system latency is almost always dominated by frame rate more than any single component, which is why raising FPS is usually the highest-impact change. If you're unsure whether your CPU or GPU is capping that frame rate, check the Bottleneck Calculator next.