Cable cross-section: mm² and AWG
How thick is the cable of my pixel string really?
What matters is the copper cross-section per core in mm². Many pixel strings are sold as “18 AWG”, which would be about 0.82 mm². Calculated from the number and diameter of the individual strands, the cross-section is often much smaller. That is why we state the cross-section of our products in mm², as it actually is.
AWG and mm² compared
| AWG | Cross-section (nominal) |
|---|---|
| 16 AWG | 1.31 mm² |
| 18 AWG | 0.82 mm² |
| 20 AWG | 0.52 mm² |
| 22 AWG | 0.33 mm² |
| 24 AWG | 0.21 mm² |
AWG (American Wire Gauge) is the US system: the higher the number, the thinner the conductor. In Europe the cross-section is given in mm².
Calculate the power feed cable
How much voltage is left at the end of the cable from the power supply to the pixels? Work out the current of your run in the guide Calculating the power supply for LED pixels.
How to work out the cross-section
- Strip a short length of insulation from one core.
- Count the strands.
- Measure the diameter of one strand, for example with a micrometer.
- Cross-section = number × 0.785 × diameter².
Example: 34 strands of 0.11 mm give 34 × 0.785 × 0.11² ≈ 0.32 mm². That is close to 22 AWG, not 18 AWG.
What this means for your installation
The thinner the wire, the more the voltage drops over its length. At the end of a run the pixels get darker or the colours shift. A single string is designed for this. If you connect several strings in a row, inject power at every connection with a T-connector (power injection). How much power you need is explained in the guide Calculating the power supply for LED pixels.
How we state the cross-section
For every product you will find the cable cross-section in the “Attributes” tab, always in mm² per core. For pixel strings it is the measured value, with the number and diameter of the strands. We do not give an AWG number as a product specification, because for pixel strings it often does not match the actual copper.
Frequently asked questions
Why do some cables say “18 AWG”?
The label is common in the pixel trade. Whether it is correct can only be checked by calculating from the number and diameter of the strands. Rely on the value in mm².
Is a smaller cross-section a defect?
No, as long as it is stated correctly and the string is fed properly. What matters is that you plan with the real value and inject power at every connection between two strings.
Do extension cables have the same cross-section?
Not necessarily. Extensions and connectors can have a different cross-section from the string. You will find the value in each product under Connectors & cables.
Not sure whether your wiring is sufficient? Tell us about your project and we will work it out with you.
Discuss your project