HDMI / DP Bandwidth

Pick resolution, frame rate, bit depth and chroma subsampling and I compute the required bandwidth (Gbps), comparing it against HDMI 1.4/2.0/2.1 and DisplayPort 1.4/2.1.

redzilla.cl — hdmi-bw

Required bandwidth

—

Gbps of video data

Pixel clock

—

total pixels × fps

Bits per pixel

—

chroma × depth

Gbps —

Minimum —

Which standard supports it?

Standard	Data capacity	Margin	Supported?

Usable data capacity per standard (channel coding already removed).

How I compute it · assumptions

1. I use the standard CEA timing totals (with blanking): 1080p→2200×1125, 4K→4400×2250, 1440p→2720×1481, 720p→1650×750. The pixel clock = totals × fps.

2. The bits per pixel come from chroma and depth: 4:4:4 = 3×bpc, 4:2:2 = 2×bpc, 4:2:0 = 1.5×bpc, with bpc = 8, 10 or 12.

3. The data bandwidth = pixel clock × bits per pixel. It is compared against the effective data capacity: HDMI 1.4 = 8.16 · HDMI 2.0 = 14.4 · HDMI 2.1 = 42.6 · DP 1.4 (HBR3) = 25.9 · DP 2.1 (UHBR20) = 77.4 Gbps.

4. These are standard totals: with Reduced Blanking (common on DisplayPort) or DSC compression the bandwidth over the cable can be noticeably lower.

Runs locally in your browser · no sign-up · nothing leaves your browser

How it works

The calculator derives the Gbps a video signal demands from four parameters: resolution (720p to 4K UHD), frames per second (24 to 120), color depth (8, 10 or 12 bits per component) and chroma subsampling (4:4:4, 4:2:2 or 4:2:0). It uses the CEA standard timing totals, which include blanking: 1080p is actually 2200×1125 pixels per frame and 4K is 4400×2250. From that it computes pixel clock = Htotal × Vtotal × fps and bandwidth = pixel clock × bits per pixel, where bits per pixel are 3, 2 or 1.5 times the depth depending on chroma.

The result is compared against the effective data capacity of each standard, with channel coding already subtracted: HDMI 1.4 = 8.16 Gbps, HDMI 2.0 = 14.4, HDMI 2.1 = 42.6, DisplayPort 1.4 (HBR3) = 25.9 and DP 2.1 (UHBR20) = 77.4 Gbps. The table marks which standards support the signal, with how much headroom, and which is the minimum sufficient one. With Reduced Blanking (common on DisplayPort) or DSC compression the actual requirement on the cable can be lower.

Example: how many Gbps does 4K60 need at 8-bit 4:4:4?

Pixel clock: 4400 × 2250 × 60 = 594 MHz.
Bits per pixel: 3 × 8 = 24 (full 4:4:4 chroma).
Bandwidth: 594 MHz × 24 bits ≈ 14.26 Gbps: it just fits HDMI 2.0 (14.4 Gbps of data), with barely +0.14 Gbps of headroom.

Frequently asked questions

Does HDMI 2.0 support 4K60 with 10-bit HDR?

At 4:4:4 it does not: the signal rises to about 17.8 Gbps and HDMI 2.0 only carries 14.4 Gbps of data. The options are dropping chroma to 4:2:2 (about 11.9 Gbps) or 4:2:0 (8.9 Gbps), which is what most players do, or moving to HDMI 2.1 or DisplayPort 1.4, which carry 4K60 10-bit 4:4:4 uncompressed.

Why is HDMI 2.0 advertised as 18 Gbps when this tool shows 14.4?

The 18 Gbps figure is the raw rate of the three TMDS channels, but 8b/10b coding spends 10 line bits for every 8 data bits: the 80 % payload leaves 14.4 Gbps of real video data. The same applies to HDMI 2.1: 48 Gbps raw with 16b/18b coding yields about 42.6 Gbps of data. This calculator always compares against data capacity, which is what matters.

What is 4:4:4, 4:2:2 and 4:2:0 chroma subsampling?

It is how much color resolution is kept relative to brightness. 4:4:4 keeps all the color (24 bits per pixel at 8-bit); 4:2:2 averages color horizontally (16 bpp) and 4:2:0 also vertically (12 bpp, half the bandwidth). For movies 4:2:0 is nearly imperceptible; for PC text or digital signage use 4:4:4, because red or blue text looks blurry with subsampling.

What happens if my signal exceeds what my cable or port supports?

Source and display negotiate over EDID and usually degrade the signal automatically: they lower chroma, depth or refresh rate (for example, 4K60 HDR falls back to 4:2:0). If the cable is the bottleneck you may see flickering or intermittent black screens. The tool table shows the exact headroom of each standard to diagnose these cases.

Was this tool useful?

Disclaimer

We take great care to keep every tool accurate and review it thoroughly; even so, we can't guarantee it is free of errors or take responsibility for how the results are used. We recommend double-checking anything critical.

Found an error? Let us know →