HDMI Bandwidth Calculator
Estimate the video data rate you need for a display mode and compare it against common HDMI limits.
What this HDMI bandwidth calculator tells you
HDMI bandwidth is the amount of data that must move from your source (PC, console, media box) to your display every second. The higher your resolution, refresh rate, color depth, and chroma quality, the higher the required bandwidth.
This calculator estimates:
- Uncompressed payload bandwidth (video data only)
- Required TMDS transport rate (used by HDMI 1.4/2.0 signaling)
- Required FRL transport rate (used by HDMI 2.1 FRL modes)
- Likely compatibility with common HDMI link capacities
How the calculation works
Core formula
The calculator starts with active pixel throughput and multiplies by bits per pixel:
Payload (Gbps) = H × V × Refresh × BitsPerPixel × (1 + BlankingOverhead) / 1,000,000,000
Then it applies optional DSC compression and converts payload to transport line rate:
- TMDS line rate ≈ payload × 1.25 (8b/10b overhead)
- FRL line rate ≈ payload × 1.125 (16b/18b overhead)
Bits per pixel by chroma
- RGB / 4:4:4: 3 × color depth
- 4:2:2: 2 × color depth (average per pixel)
- 4:2:0: 1.5 × color depth (average per pixel)
Typical modes (rough estimates)
| Mode | Format | Estimated Payload | Estimated TMDS Line Rate |
|---|---|---|---|
| 1920×1080 @ 60 | 8-bit 4:4:4 | ~3.58 Gbps | ~4.48 Gbps |
| 2560×1440 @ 144 | 8-bit 4:4:4 | ~15.29 Gbps | ~19.11 Gbps |
| 3840×2160 @ 60 | 10-bit 4:4:4 | ~17.92 Gbps | ~22.40 Gbps |
| 3840×2160 @ 120 | 10-bit 4:2:0 | ~17.92 Gbps | ~22.40 Gbps |
| 7680×4320 @ 60 | 10-bit 4:2:0 | ~35.83 Gbps | ~44.79 Gbps |
HDMI version limits in practical terms
HDMI 1.4
Max TMDS line rate is 10.2 Gbps. Great for 1080p and many 1440p/4K30 scenarios, but not enough for high-frame-rate 4K.
HDMI 2.0
Max TMDS line rate is 18 Gbps. This is the classic “4K60” generation, typically with tradeoffs in chroma and/or bit depth depending on timing.
HDMI 2.1 (FRL)
FRL modes scale to 24/32/40/48 Gbps raw line rate, enabling 4K120 and 8K formats, especially when combined with DSC on demanding modes.
Why your real-world result may differ
- Timing standard: CVT-RB and CTA timings have different blanking overhead.
- GPU/display support: Not all ports support every FRL lane/rate.
- Cable quality: Longer or lower-quality cables can fail at high rates.
- Firmware behavior: Devices may force 4:2:0 or lower bit depth to keep signal stable.
- DSC support: Must be supported by both source and sink to be used.
Practical tips to reduce HDMI bandwidth requirement
- Drop from 12-bit to 10-bit or 8-bit when visually acceptable.
- Use 4:2:2 or 4:2:0 for video playback use cases.
- Lower refresh rate slightly (e.g., 144 Hz to 120 Hz).
- Enable DSC if both devices support it.
- Use certified Ultra High Speed HDMI cables for HDMI 2.1 targets.
Quick FAQ
Is HDMI 2.1 always 48 Gbps?
No. HDMI 2.1 devices can implement different FRL rates. Some top out below 48 Gbps.
Can HDMI 2.0 do 4K120?
Generally no for full-quality uncompressed formats. The required transport rate usually exceeds 18 Gbps TMDS.
What is the safest planning approach?
Target some headroom above your calculated requirement, verify source + display format support, and use high-quality certified cables.