Refresh Rate & Response Time Calculator
Turn a monitor refresh rate into its frame window in milliseconds and check whether the panel’s pixel response time is fast enough to avoid ghosting.
How it works
Frame window (ms) = 1000 ÷ refresh rate · Headroom = frame window − response time
Refresh rate sets how often the screen redraws — a 144 Hz panel starts a new frame every 6.94 ms. For a frame to be clean, every pixel must finish its color transition (the gray-to-gray response time) before the next frame arrives. When the response time approaches or exceeds the frame window, the previous image has not fully cleared and you see smearing or "ghosting" behind moving objects.
Worked example
A 144 Hz monitor has a frame window of 1000 ÷ 144 = 6.944 ms. A 4 ms GtG response uses 4 ÷ 6.944 = 58% of that window, leaving 2.9 ms of headroom — comfortable. A slow 10 ms panel would overshoot the 6.944 ms window and ghost noticeably at 144 Hz.
Frequently asked questions
Does a fast response time raise my frame rate?
No. Response time only affects how cleanly each frame transitions; the refresh rate (Hz) sets how many frames per second the display can show. A slow response on a high-Hz panel produces blur, not fewer frames.
What response time do I need for 240 Hz?
A 240 Hz frame window is 1000 ÷ 240 = 4.17 ms, so you want a real-world GtG response comfortably under that — ideally 2–3 ms. Marketed "1 ms" figures are often best-case and measured differently, so leave headroom.
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This calculator is for educational purposes. Double-check important results before acting on them.