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Hi everyone one more time, I have a silly question about trace length measurement on Altium. I was using the PCB tab to measure the length of the traces (on mm). Measuring PCIE_REFCLK_P on the tab de value is 14.072.

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But I realized that If I use Reports>Measure selected objects I see this:

enter image description here

The measurement is almost 4 mm less, which is the good measurement or the measurement I should to use? Thank you so much!

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  • \$\begingroup\$ Is your question the difference between mm and mil? If so, because the USA insists on using nonsense units, we're stuck with a bastardisation of metric and imperial: the mil! One mil is 1000th of an inch, so your numbers are the same. \$\endgroup\$
    – awjlogan
    Apr 30 '21 at 8:16
  • \$\begingroup\$ No, Is that not the question, and not the same numbers. On PCB tab PCIE_REFCLK_P length is 14.072 as "Routed". Using Reports > Measure select objects the length is 10.741 mm. \$\endgroup\$
    – Juanma
    Apr 30 '21 at 8:27
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    \$\begingroup\$ Got it, that needed clarifying :) \$\endgroup\$
    – awjlogan
    Apr 30 '21 at 8:31
  • \$\begingroup\$ Sorry for the misunderstanding, I´m going to edit the post. \$\endgroup\$
    – Juanma
    Apr 30 '21 at 8:32
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    \$\begingroup\$ On an unrelated note, I don't recommend putting vias that large over SMT pads that small. Solder will wick through the via barrel and will not flow properly around the component leads, causing a poor (or nonexistent) joint \$\endgroup\$
    – DerStrom8
    Apr 30 '21 at 11:16
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Net length takes vias in account.

Via length is equal to PCB thickness according to ALtium.

Net Length = Distance measured (with Reports>Measure) + Number of vias * PCB thickness

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  • \$\begingroup\$ Thank you so much! I was afraid because I have used the Net Routed Value. \$\endgroup\$
    – Juanma
    Apr 30 '21 at 12:44

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