Monitor response time vs refresh rate calculator
A 240 Hz monitor with a slow panel can smear as much as a 144 Hz one. Enter the refresh rate and the grey to grey response time. See whether the pixels finish changing before the next frame arrives.
Why response time and refresh rate must match
A monitor draws a new frame every so many milliseconds. At 144 Hz that is 6.94 milliseconds, at 240 Hz it is 4.17, and at 360 Hz it is 2.78. The panel pixels need time to change colour, and the grey to grey figure says roughly how long that takes. If the pixels need longer than a frame, they are still moving when the next frame arrives, so the image smears and the higher refresh rate gives you less than it promises.
This calculator divides the response time by the frame interval. A result under about 80 percent means the pixel settles before the next frame and you get the full benefit of the refresh rate. Over 100 percent means the panel cannot keep up.
Frame interval at common refresh rates
The time each frame stays on screen. A panel needs to change colour in clearly less than this to look sharp.
| Refresh rate | Frame interval | Response time to keep under 80% |
|---|---|---|
| 60 Hz | 16.67 ms | 13.3 ms |
| 144 Hz | 6.94 ms | 5.6 ms |
| 240 Hz | 4.17 ms | 3.3 ms |
| 360 Hz | 2.78 ms | 2.2 ms |
Reading response time claims
Response time is quoted in different ways. Grey to grey, often shortened to GtG, measures the change between two shades of grey, and the headline figure is usually the fastest transition, sometimes with the strongest overdrive turned on. Black to white and the average across many transitions are slower. OLED panels change colour in a fraction of a millisecond, which is why they look so clear at high refresh rates, while some older LCD technologies take much longer on dark transitions.
For purchases, reviews that measure the average response time and overshoot give a better picture than the box. Combine that with this calculator to see where the panel fits. For matching a monitor to your card, use the monitor and GPU matcher.
Getting the most from your monitor
Turn on the monitor overdrive setting at its middle level, and check the result with a motion test pattern. Too much overdrive makes bright trails behind moving objects, which looks worse than the blur it was meant to fix. Make sure your cable and settings actually deliver the refresh rate you paid for, which you can check with the cable bandwidth calculator.
Frame rate matters just as much. A high refresh rate shows its benefit only when the game produces frames to match, so look at the frame time converter and the VRR frame cap calculator to match them.
How to use the response time vs refresh rate
- Enter the refresh rate of the monitor in hertz.
- Enter the grey to grey response time from the specification, in milliseconds.
- Read how much of each frame the pixel needs to finish changing.
- Check the highest useful refresh rate for that panel.
- Compare other refresh rates in the table before you buy.
Common mistakes to avoid
- Buying on the refresh rate alone and ignoring the panel speed.
- Trusting a 1 ms rating that was measured on one best-case transition.
- Maxing out overdrive, which adds overshoot and trails.
Related tools and guides
Keep going with these: VRR and frame cap calculator, FPS to frame time converter, monitor and GPU matcher, Monitor viewing distance and angle calculator, does frame generation add input lag.
Frequently asked questions
Is 1 ms response time good?
It is fast, but check how it was measured. Many 1 ms ratings are best-case grey to grey figures with strong overdrive, so average blur is usually worse. A genuine fast panel such as OLED can reach well under a millisecond, which suits very high refresh rates.
What response time do I need for 144 Hz?
The frame interval at 144 Hz is 6.94 milliseconds, so a panel with an average response of about 5 milliseconds or less keeps up. Anything much slower will smear on dark transitions even though the refresh rate looks high on paper.
Does higher refresh rate reduce motion blur?
Only if the pixels can keep up and your game reaches that frame rate. Each frame stays on screen for less time at higher refresh rates, which reduces the blur your eyes perceive, but a slow panel or low fps wastes the gain.
What is overdrive on a monitor?
Overdrive pushes pixels harder to change colour, which shortens response time. Too little leaves blur, and too much causes overshoot, with bright or dark trails behind moving objects. A middle setting is usually the best compromise, and many monitors have an adaptive option for varied refresh rates.
Why does my 240 Hz monitor still look blurry?
A slow panel, an unsuitable overdrive setting or a game running well below 240 frames per second can each cause blur. Check the response time against the frame interval here, set overdrive to the middle level and confirm the refresh rate in Windows.
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