Gaming Calculators
Response time vs refresh rate.
A monitor refreshes every 1000 / Hz milliseconds. If its pixels take longer than that to change, the old image is still fading when the next one arrives. Enter the refresh rate and the quoted response time to see how they compare. Runs in your browser; nothing is sent or stored.
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Worked example
A 144 Hz monitor refreshes every 1000 / 144 = 6.94 ms. With a 4 ms response time, the pixels take 58% of one refresh to change, and a 4 ms response could in principle keep up with up to 250 Hz. A 240 Hz panel refreshes every 4.17 ms, so an 8 ms response uses 192% of a refresh and is slower than one refresh interval, which is where smearing and ghosting become likely.
How it works
Refresh interval (ms) = 1000 / refresh rate (Hz), and the response share is response time / refresh interval. This page rates the result as well within (half a refresh or less), within (up to one refresh) or exceeding (more than one refresh). That cut-off is a common rule of thumb for comparing the two numbers, not a published standard, and it ignores overshoot, panel type and how the maker measured the figure.
The Display motion blur - Wikipedia article lists slow pixel response times as a cause of visible ghosting or smearing that gets more pronounced as motion gets faster. The Refresh rate - Wikipedia article gives frame persistence of approximately 6.9 ms at 144 Hz and 16.7 ms at 60 Hz, matching the interval figures here.
Sources: Display motion blur - Wikipedia; Refresh rate - Wikipedia. Each opened 2026-10-08.
Planning guide only, not professional advice. Figures are estimates from the inputs you enter.
FAQ
Should response time be lower than the refresh interval?
As a rule of thumb, yes: the pixels should finish changing before the next refresh. At 144 Hz that is 6.94 ms and at 240 Hz it is 4.17 ms. This is a common guideline, not a published standard.
Is 1 ms response time enough for 240 Hz?
On paper, yes: 1 ms is well inside the 4.17 ms refresh interval at 240 Hz. In practice makers quote best-case gray-to-gray figures, so check independent measurements.
What is GtG response time?
Gray-to-gray is the time a pixel takes to change from one shade of gray to another. It is the most common figure on spec sheets, but different makers choose different thresholds and transitions.
Does a higher refresh rate need a faster panel?
Yes. Each refresh interval gets shorter, so pixel transitions have less time to complete before the next frame. Slow transitions show up as ghosting or smearing in fast motion.
Does response time affect input lag?
Not directly. Response time is how fast pixels change colour, while input lag is the delay between your input and the picture changing. They are measured separately.