PlayInfoBox

Home /Converter /How Refresh Rate (Hz) and Frame Time (ms) Relate

How Refresh Rate (Hz) and Frame Time (ms) Relate

Refresh rate and frame time describe the same thing from two different angles, and the relationship between them explains why higher refresh rates deliver diminishing returns.

Frame time (ms) = 1000 Γ· refresh rate (Hz)

A 60Hz display refreshes every 1000 Γ· 60 β‰ˆ 16.67 ms. A 144Hz display refreshes every 1000 Γ· 144 β‰ˆ 6.94 ms, and a 240Hz display every 1000 Γ· 240 β‰ˆ 4.17 ms.

Each step up in Hz saves progressively fewer milliseconds

Going from 60Hz to 120Hz saves about 8.3 ms per frame, a large relative jump. Going from 120Hz to 240Hz only saves about another 4.2 ms, which is why higher refresh rates feel like smaller improvements even though the Hz numbers look similarly large.

Refresh rate is a display capability; frame rate is what is actually being rendered

A 144Hz monitor can refresh up to 144 times per second, but if a game is only rendering 60 frames per second, the display still shows the same rendered frame more than once per refresh cycle rather than magically creating new frames.

A target frame rate sets a strict rendering time budget

To sustain 60 fps, every frame must finish rendering within 16.67 ms; to sustain 144 fps, that budget shrinks to 6.94 ms. Missing the budget on any given frame causes a stutter or a dropped frame.

Variable refresh rate technology syncs the display to the frame rate instead

Adaptive sync technologies (commonly marketed as G-Sync or FreeSync) let the display's refresh rate vary to match the GPU's actual output frame by frame, reducing the screen tearing or stutter that happens when a fixed refresh rate and a fluctuating frame rate fall out of step.

Why 60 to 144Hz feels like a bigger leap than 144 to 240Hz

Because frame time is an inverse relationship with Hz, equal-sounding jumps in refresh rate do not produce equal jumps in frame time. The difference between 60Hz and 144Hz is about 9.7 ms per frame, while the difference between 144Hz and 240Hz is only about 2.8 ms β€” a much smaller absolute change, which is why upgrading from an already-high refresh rate tends to feel like a smaller improvement in practice.

Why matching refresh rate and frame rate matters more than either number alone

A high-refresh-rate monitor paired with a much lower frame rate does not deliver the smoothness that the Hz number implies, since the display is simply repeating frames rather than showing new content more often. Getting the benefit of a high refresh rate requires a frame rate that can actually keep pace, or a variable refresh rate technology that adapts the display to whatever frame rate is actually achievable.

Frequently Asked Questions

Why does going from 60Hz to 144Hz feel like such a big jump, but 144Hz to 240Hz feels smaller?

Because frame time shrinks in an inverse, non-linear relationship to Hz. The millisecond gap between 60 and 144Hz is much larger than the millisecond gap between 144 and 240Hz, even though both jumps look similarly large in raw Hz numbers.

What happens if my GPU renders fewer frames per second than my monitor's refresh rate?

Without adaptive sync, the display repeats the most recent frame to fill the extra refresh cycles, and mismatched timing can cause visible tearing or stutter. Variable refresh rate technology (G-Sync or FreeSync) reduces this by syncing the display's refresh timing to the GPU's actual frame output.