240Hz Test – Check Your Monitor Runs at 240Hz (4.17 ms Frame Time)

240Hz Refresh Rate Test

Check whether your display is really running at 240Hz, and see what 240Hz means in frame time and smoothness.

A 240Hz display refreshes 240 times per second, showing a new frame every 4.17 ms, 4.0× as often as a 60Hz screen.

Current FPS

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Frames in the last second

Refresh rate

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Nearest standard rate

Average FPS

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Since the test started

1% low FPS

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Slowest 1% of frames

Frame time

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Typical (median)

Jitter

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Lower is smoother

Dropped frames

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Frames that arrived late

Frames

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Measured so far

FPS over the last 10 seconds. The dashed line is your refresh rate; red marks are dropped frames.

Speed

Stress test: 0 moving marbles

Adds drawing work to every frame. Raise it until the FPS drops to see how much your device can draw at full speed.

240Hz in numbers

Refreshes per second	240
Time per frame	4.17 ms
Compared with 60Hz	4.00× as many frames, 12.50 ms less per frame
FPS needed to use every refresh	240
Half-rate V-Sync cap	120 FPS

Is 240Hz good?

Yes, for competitive play, where every millisecond of display delay matters. To benefit, your games need to run at or near 240 FPS.

You'll find 240Hz on esports and high-end gaming monitors.

Getting a steady 240Hz

Choose 240Hz in your operating system's display settings; many monitors ship set to 60Hz.
Use a cable and port with enough bandwidth. High refresh rates at high resolutions usually need DisplayPort or HDMI 2.1.
In games, aim for at least 240 FPS, or turn on G-Sync/FreeSync so lower frame rates still look smooth.
Run the test above: the refresh rate box should read 240 Hz with low jitter.

Other refresh rates

Refresh rate	Frame time	vs 60Hz
60Hz	16.67 ms	1.00×
75Hz	13.33 ms	1.25×
90Hz	11.11 ms	1.50×
100Hz	10.00 ms	1.67×
120Hz	8.33 ms	2.00×
144Hz	6.94 ms	2.40×
165Hz	6.06 ms	2.75×
180Hz	5.56 ms	3.00×
240Hz	4.17 ms	4.00×
360Hz	2.78 ms	6.00×
480Hz	2.08 ms	8.00×

Frequently asked questions

What is the frame time at 240Hz?

At 240Hz a new frame appears every 4.17 ms (1000 ÷ 240).

Is 240Hz good for gaming?

Yes, for competitive play, where every millisecond of display delay matters. To benefit, your games need to run at or near 240 FPS.

How many FPS do I need for 240Hz?

To use every refresh, your game should render at least 240 frames per second. Below that, the monitor shows some frames twice; variable refresh rate (G-Sync or FreeSync) keeps that smooth.

How do I check if my monitor is running at 240Hz?

Run the test on this page: the "Refresh rate" box shows the rate your display is actually using. If it reads lower than 240Hz, select 240Hz in your display settings and check that your cable supports it.