Calculate monitor bandwidth from resolution, bit depth, refresh rate, and screen count, plus estimate HDMI and DisplayPort compatibility.
Monitor Bandwidth Formula
The basic monitor bandwidth calculation multiplies the number of pixels sent per frame by the number of bits used for each pixel, the refresh rate, and the number of screens.
BW_MBps = (P * B * R * N) / (8 * 1000000)
For the interface compatibility mode, the calculator uses width and height directly and adjusts bits per pixel based on color depth and chroma subsampling.
DataRate_Gbps = (W * H * BPC * CF * R * N) / 1000000000
- BW_MBps = bandwidth in megabytes per second
- DataRate_Gbps = active-video data rate in gigabits per second
- P = total pixels per frame, such as 1920 × 1080 = 2,073,600 pixels
- W = screen width in pixels
- H = screen height in pixels
- B = bit depth per pixel, such as 24 bits for 8-bit RGB 4:4:4
- BPC = bits per color channel, such as 8-bit, 10-bit, or 12-bit
- CF = chroma factor: 3 for 4:4:4, 2 for 4:2:2, and 1.5 for 4:2:0
- R = refresh rate in hertz
- N = number of screens
In the monitor bandwidth tab, you can leave one field empty and calculate it from the other four values. The calculator converts resolution, bit depth, refresh rate, and bandwidth units before solving the formula.
In the interface compatibility tab, the result is a minimum active-video data rate. It does not include blanking intervals, protocol overhead, link encoding losses, or compression such as DSC.
Common Monitor Resolution and Pixel Counts
| Resolution | Name | Pixels per Frame | Megapixels |
|---|---|---|---|
| 1280 × 720 | HD | 921,600 | 0.92 MP |
| 1920 × 1080 | Full HD | 2,073,600 | 2.07 MP |
| 2560 × 1440 | QHD | 3,686,400 | 3.69 MP |
| 3840 × 2160 | 4K UHD | 8,294,400 | 8.29 MP |
| 7680 × 4320 | 8K UHD | 33,177,600 | 33.18 MP |
Approximate Video Interface Payload Limits
| Interface | Approximate Payload | Use in the Calculator |
|---|---|---|
| HDMI 1.4 | 8.16 Gbit/s | Older 1080p and some limited 4K modes |
| HDMI 2.0 | 14.4 Gbit/s | Common for 4K 60 Hz 8-bit with suitable settings |
| HDMI 2.1 FRL | 42.67 Gbit/s | Higher refresh 4K and some 8K modes |
| DisplayPort 1.2 | 17.28 Gbit/s | Common for QHD high refresh and 4K 60 Hz |
| DisplayPort 1.4 | 25.92 Gbit/s | Higher bandwidth modes, often with DSC for demanding settings |
| DisplayPort 2.1 UHBR20 | 77.58 Gbit/s | Very high refresh, high resolution, and multi-monitor use |
Example Calculations
Example 1: 4K at 60 Hz, 24 bits per pixel
You want the bandwidth for one 3840 × 2160 monitor at 60 Hz using 24 bits per pixel.
- Resolution: 3840 × 2160 = 8,294,400 pixels
- Bit depth: 24 bits per pixel
- Refresh rate: 60 Hz
- Number of screens: 1
BW_MBps = (8294400 * 24 * 60 * 1) / (8 * 1000000)
The result is 1492.992 MB/s, which is about 11.94 Gbit/s.
Example 2: 1440p at 144 Hz, 10-bit 4:4:4
You want the interface data rate for one 2560 × 1440 monitor at 144 Hz, 10-bit per channel, using 4:4:4 chroma.
- Width: 2560 pixels
- Height: 1440 pixels
- Bits per color channel: 10
- Chroma factor for 4:4:4: 3
- Refresh rate: 144 Hz
- Number of screens: 1
DataRate_Gbps = (2560 * 1440 * 10 * 3 * 144 * 1) / 1000000000
The result is 15.93 Gbit/s before blanking and overhead.
FAQs
Why is the calculated bandwidth lower than what a video cable specification lists?
The calculator gives the active-video data rate unless you are using the basic bandwidth tab with your own assumptions. Real video links often need more bandwidth because of blanking intervals, link encoding, packet overhead, and timing standards. Cable and port specifications usually describe link capacity, not only the visible pixel data.
What bit depth should you enter for a normal monitor?
For standard 8-bit RGB 4:4:4 video, use 24 bits per pixel in the basic tab because there are 8 bits for red, 8 bits for green, and 8 bits for blue. For 10-bit RGB 4:4:4, use 30 bits per pixel. In the interface tab, choose the per-channel color bit depth and chroma setting instead.
Does chroma subsampling reduce monitor bandwidth?
Yes. Chroma subsampling sends less color detail than full 4:4:4 color, so it reduces the required data rate. In the interface tab, 4:4:4 uses a chroma factor of 3, 4:2:2 uses 2, and 4:2:0 uses 1.5. For desktop text and general computer use, 4:4:4 usually gives the clearest result.
