HDMI Impedance Calculator
HDMI 1.4 | HDMI 2.0 | HDMI 2.1
Review routing guidance for HDMI. Numeric differential calculation is temporarily unavailable; confirm pair geometry with a validated field solver and your fabricator.
HDMI Data Rates and Nominal Impedance
| HDMI Version | Bandwidth | Max Resolution | Nominal Differential Z |
|---|---|---|---|
| HDMI 1.4 | 10.2 Gbps | 4K@30Hz | 100Ω |
| HDMI 2.0 | 18 Gbps | 4K@60Hz | 100Ω |
| HDMI 2.1 | 48 Gbps | 8K@60Hz | 100Ω |
HDMI PCB Design Guidelines
100Ω Differential
The nominal differential impedance target for HDMI TMDS data and clock pairs is 100Ω; confirm coupled-pair geometry independently.
4 Differential Pairs
HDMI TMDS uses 4 differential pairs: 3 TMDS data channels + 1 TMDS clock. Check the current interface specification and your SoC/PHY datasheet for routing constraints.
Length Matching
Tolerance and intra-pair / inter-pair skew budgets are defined in the current interface specification and your SoC/PHY datasheet; check them there. This page does not state them.
HDMI Signal Types
TMDS Signals
- • Data 0/1/2: 100Ω differential, high-speed
- • Clock: 100Ω differential
- • Check intra-pair and inter-pair skew budgets in your SoC/PHY datasheet
- • Keep away from noise sources
- • Route on inner layers if possible
Low-Speed Signals
- • DDC (I2C): Not impedance critical
- • CEC: Single-ended, low-speed
- • HPD: Hot Plug Detect, GPIO
- • +5V/GND: Power, standard traces
- • Standard routing rules apply
Review Your HDMI Stackup
Use the impedance calculator for isolated-line single-ended estimates. Differential width and spacing calculations are temporarily unavailable; use a validated coupled-line solver.
Source note: the impedance values on this page are the nominal targets commonly cited for this interface. This site does not reproduce the standard's text and has not verified them against it. Confirm them, with tolerances and skew budgets, in the current HDMI specification (licensed document) (the HDMI Licensing Administrator) and your SoC/PHY datasheet.
HDMI Design FAQ
What impedance do I need for HDMI?
The nominal differential impedance target for HDMI TMDS data and clock pairs is 100Ω. Tolerance and intra-pair / inter-pair skew budgets are defined in the current interface specification and your SoC/PHY datasheet; check them there. This page does not state them.
How long can HDMI traces be?
Check the current interface specification and your SoC/PHY datasheet for channel length constraints; this page does not state a trace-length limit. Check the current interface specification and your SoC/PHY datasheet for PCB material requirements for your channel.
Do I need controlled impedance for HDMI 1.4?
Check the current HDMI specification and your SoC/PHY datasheet for controlled-impedance requirements. Tolerance and intra-pair / inter-pair skew budgets are defined in the current interface specification and your SoC/PHY datasheet; check them there. This page does not state them.
Can I route HDMI on outer layers?
Yes, but inner layers (stripline) provide better shielding. If routing on outer layers, ensure adequate ground pour on adjacent layers.
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