Quick answer
With the default example, 3,840 x 2,160 at 120 Hz, 10-bit, 4:4:4 needs about 31.4 Gbps with the selected overhead and compression settings.The selected 48 Gbps limit is marked as bandwidth fits.
- Video mode
- 3,840 x 2,160 @ 120 Hz
- Estimated bandwidth
- 31.4 Gbps
- Bandwidth use
- 65% of 48 Gbps
- Recommended tier
- HDMI FRL 32 Gbps
How to use this HDMI cable bandwidth calculator
Enter the resolution, refresh rate, color depth, chroma format, timing overhead, compression mode, and the lowest HDMI bandwidth limit in your chain. The lowest limit may be the cable, source port, display input, adapter, AV receiver, switch, or capture card.
The calculator estimates the video signal bandwidth and compares it with common HDMI bandwidth tiers. It is most useful for questions such as 4K 120Hz, 4K 144Hz, 8K 60Hz, HDR 10-bit output, RGB versus 4:2:2, and whether DSC is likely needed.
If your main question is whether a resolution upgrade is visible, use the TV Resolution Calculator. For desktop sharpness, use the Monitor PPI Calculator.
HDMI bandwidth formula
bits per pixel = bits per color x 3 x chroma factoractive video Gbps = width x height x refresh rate x bits per pixel / 1,000,000,000estimated uncompressed Gbps = active video Gbps x (1 + timing overhead %)estimated signal Gbps = estimated uncompressed Gbps / DSC compression ratiobandwidth use % = estimated signal Gbps / available HDMI bandwidth x 100Chroma factor is 1.0 for 4:4:4 or RGB, 2/3 for 4:2:2, and 1/2 for 4:2:0. The timing overhead input is a planning allowance for blanking and video timing differences. Exact HDMI support still depends on the actual source, display, cable, firmware, and negotiated mode.
Assumptions and methodology
HDMI bandwidth is not just a cable label. A 4K 120Hz signal can fail if any part of the chain is limited, including the GPU or console output, TV or monitor input, receiver, adapter, capture device, firmware setting, or cable certification.
- The calculator estimates signal bandwidth from active pixels, refresh rate, color depth, chroma format, timing overhead, and optional DSC compression.
- HDMI 2.1 Ultra High Speed cable certification is commonly associated with up to 48 Gbps system configurations.
- HDMI 2.2 Ultra96 introduces 64, 80, and 96 Gbps maximum bandwidth indicators for higher-end applications.
- A certified cable does not guarantee the source and display ports support the same mode.
- DSC can lower the bandwidth estimate, but only when both ends support the same compressed mode.
Example calculations
4K 120Hz HDR HDMI bandwidth example
A 3840 x 2160 signal at 120 Hz, 10-bit color, and 4:4:4 chroma has an active video payload of about 29.9 Gbps. With the default 5% timing overhead, the estimate becomes 31.4 Gbps.
That is above HDMI 2.0-class 18 Gbps planning range and fits much more naturally into a 40 or 48 Gbps HDMI 2.1-class setup. This is why 4K 120Hz HDR gaming usually requires both compatible HDMI 2.1 ports and an Ultra High Speed HDMI cable, not just any cable that physically plugs in.
Common HDMI bandwidth examples
These examples use the same estimating method as the calculator. Real device support can still vary by timing, DSC, EDID, and port implementation.
| Signal | Format | Compression | Estimate | Recommended tier | Read |
|---|---|---|---|---|---|
| 3,840 x 2,160 60 Hz | 8-bit 4:4:4 | None | 12.5 Gbps | Premium High Speed HDMI / 18 Gbps | Bandwidth fits |
| 3,840 x 2,160 120 Hz | 10-bit 4:4:4 | None | 31.4 Gbps | HDMI FRL 32 Gbps | Bandwidth fits |
| 3,840 x 2,160 144 Hz | 10-bit 4:4:4 | None | 37.6 Gbps | HDMI FRL 40 Gbps | Bandwidth fits |
| 7,680 x 4,320 60 Hz | 10-bit 4:4:4 | None | 62.7 Gbps | Ultra96 HDMI / 64 Gbps | Bandwidth fits |
| 7,680 x 4,320 60 Hz | 10-bit 4:4:4 | 3:1 DSC | 20.9 Gbps | HDMI FRL 24 Gbps | Bandwidth fits |
HDMI 2.0, HDMI 2.1, and HDMI 2.2 bandwidth
HDMI 2.0-era 18 Gbps bandwidth is often enough for 4K 60Hz with common video settings, but it is not enough for many 4K 120Hz HDR 4:4:4 modes. HDMI 2.1-class 40 or 48 Gbps links are the practical target for many high-refresh 4K gaming displays. HDMI 2.2 Ultra96 adds 64, 80, and 96 Gbps maximum bandwidth indicators for future high-resolution and high-refresh formats.
The safest buying rule is to compare the actual bandwidth number and certification label, then confirm that both devices support the exact mode you want. Marketing terms alone are not enough.
DSC, chroma subsampling, and image quality tradeoffs
If a signal does not fit uncompressed, devices may use DSC or reduce chroma detail. DSC is designed to preserve image quality, but support must exist on both ends. Chroma subsampling can be acceptable for video, yet 4:2:2 and 4:2:0 can make desktop text and fine UI edges look worse than 4:4:4 or RGB.
For PC monitor use, prioritize full RGB or 4:4:4 when possible. For TV video playback, reduced chroma may be less noticeable, depending on content and viewing distance.
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FAQ
How much HDMI bandwidth do I need for 4K 120Hz?
For 4K 120Hz at 10-bit 4:4:4 with a small timing overhead, the estimate is about 31 Gbps before protocol details. That is above HDMI 2.0-class 18 Gbps bandwidth and usually points to an HDMI 2.1-class 40 or 48 Gbps link, unless DSC or reduced color settings are used.
Do I need HDMI 2.1 for 4K 120Hz?
Usually yes for 4K 120Hz with HDR and full 4:4:4 or RGB color. Some devices can use reduced chroma or DSC, but for gaming PCs, consoles, and TVs, an Ultra High Speed HDMI cable and compatible HDMI 2.1 ports are the practical target.
Is HDMI 2.0 enough for 4K 60Hz HDR?
It can be, depending on the color format. 4K 60Hz 8-bit 4:4:4 is commonly within 18 Gbps planning range, while 10-bit HDR at full 4:4:4 may be tight or above that limit. Many devices use 4:2:2 or 4:2:0 for 4K HDR over 18 Gbps links.
What HDMI cable do I need for 8K?
For uncompressed 8K 60Hz with high color quality, the estimate can exceed 48 Gbps and point toward HDMI 2.2 Ultra96-class bandwidth. HDMI 2.1 48 Gbps setups may rely on DSC or reduced color settings for some 8K modes.
Does an HDMI cable version guarantee performance?
No. The cable, source port, display port, adapter, receiver, switch, and firmware must all support the required mode. Certification labels such as Ultra High Speed HDMI or Ultra96 HDMI are more useful than vague marketing terms.
What is chroma subsampling and why does it affect HDMI bandwidth?
Chroma subsampling reduces color resolution. 4:4:4 keeps full color detail, 4:2:2 uses less bandwidth, and 4:2:0 uses less again. Video can look acceptable with subsampling, but desktop text and fine UI edges usually look best at 4:4:4 or RGB.
What is DSC in HDMI bandwidth calculations?
DSC means Display Stream Compression. It can reduce required bandwidth while preserving high resolutions and refresh rates, but it only works when the source, display, and selected HDMI mode all support it.
Why is this an estimate instead of an exact HDMI pass/fail test?
Exact HDMI support depends on detailed video timings, blanking intervals, EDID, color format negotiation, DSC implementation, firmware, cable quality, and any devices between the source and display. The calculator gives a practical planning estimate before testing the actual setup.