HDMI and DisplayPort bandwidth calculator
Will your monitor reach its full refresh rate over the cable you have? Pick the resolution, refresh rate and colour depth. See the bandwidth needed and which HDMI and DisplayPort versions can carry it.
How video bandwidth is worked out
Every pixel on screen is sent as a set of colour values, every frame. Multiply the number of pixels by the refresh rate and the bits per pixel and you get the data rate. At 4K and 60 Hz with 8 bits for each of red, green and blue, that is 3840 times 2160 times 60 times 24, close to 11.9 billion bits per second. Real signals also carry blanking intervals that are not part of the picture, so the calculator adds an allowance, about 5 percent for modern timings, giving 12.5 gigabits per second.
Compare that with what each link can actually carry. A link has a headline rate, but encoding takes a share of it, so the usable figures in the calculator are lower than the marketing numbers.
Bandwidth for common signals (8 bit RGB, 5% blanking)
Approximate data rates for popular resolutions and refresh rates before compression.
| Signal | Bandwidth | Smallest link that carries it |
|---|---|---|
| 1080p 240 Hz | 12.5 Gbps | HDMI 2.0 |
| 1440p 165 Hz | 15.3 Gbps | DisplayPort 1.4 |
| 4K 60 Hz | 12.5 Gbps | HDMI 2.0 |
| 4K 144 Hz | 30.1 Gbps | DisplayPort 2.1 UHBR10 or HDMI 2.1 |
Which cable for which monitor
HDMI 2.0 can carry 4K at 60 Hz in full colour but not 4K at 144 Hz. HDMI 2.1 raises the limit a long way, and so does DisplayPort 1.4, which many gaming monitors use, especially with compression for the highest refresh rates. DisplayPort 2.1 pushes further still, which matters for high refresh rate 4K and beyond. Which of these your graphics card and monitor offer is stated in their specifications, so check both ends before you buy a cable.
Compression such as Display Stream Compression reduces the data sent with very little visible difference to most people, and is why many monitors reach high refresh rates on links that could not carry the raw signal. This calculator shows the uncompressed case so you can see when compression is needed.
Getting the refresh rate you paid for
If Windows will not offer the refresh rate you expect, go through the chain: the port on the card, the cable, the port on the monitor and the monitor menu setting that enables the faster mode. Plug into the right port on the card, because some monitors have one input that supports the full rate and another that does not. Then confirm the rate under advanced display settings.
Once the signal is right, make sure the panel can keep up with the response time calculator, and that your card can push the frames with the monitor and GPU matcher.
How to use the hDMI and DisplayPort bandwidth calculator
- Pick the resolution of your monitor.
- Enter the refresh rate you want to run.
- Choose 8 bit or 10 bit colour. HDR usually uses 10 bit.
- Leave chroma at full RGB unless you want to lower the bandwidth.
- Read which cable standards can carry the signal without compression.
Common mistakes to avoid
- Assuming any HDMI port supports every refresh rate. The version decides.
- Ignoring the cable itself, which can be older than the port.
- Forgetting that 10 bit colour adds a quarter more data than 8 bit.
Related tools and guides
Keep going with these: Response time vs refresh rate calculator, monitor and GPU matcher, VRR and frame cap calculator, monitor PPI calculator, best graphics cards guide.
Frequently asked questions
Can HDMI 2.0 do 4K at 144 Hz?
Not without compression. 4K at 144 Hz in full colour needs about 30 gigabits per second, and HDMI 2.0 carries about 14.4 usable. With 4:2:0 colour or compression it can be possible, but HDMI 2.1 or DisplayPort is the proper route.
How much bandwidth does 4K 60 Hz need?
About 12.5 gigabits per second with 8 bit colour and a typical blanking allowance. That fits HDMI 2.0 and DisplayPort 1.4 easily. HDR at 10 bit needs about a quarter more, which still fits both of those standards, so a good cable is the only thing to check.
Is DisplayPort better than HDMI for gaming?
DisplayPort 1.4 carries more than HDMI 2.0 and is common on gaming monitors, while HDMI 2.1 carries more again and suits consoles and televisions. Pick the version that supports your resolution and refresh rate, then check your card and monitor both have it.
What is Display Stream Compression?
It is a compression method that reduces the video data sent over a link with very little visible loss. It lets cables carry high resolutions and refresh rates that would not fit uncompressed. Both the graphics card and monitor must support it, and it can limit some features.
Why can I not select 144 Hz in Windows?
The usual causes are a cable or port that does not support the signal, the wrong input on the monitor, or a monitor setting that needs enabling. Check the version of each link against the bandwidth shown here, then confirm under advanced display settings.
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