# About length track measurement - Altium

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.

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

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

• 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. Apr 30 '21 at 8:16
• 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. Apr 30 '21 at 8:27
• Got it, that needed clarifying :) Apr 30 '21 at 8:31
• Sorry for the misunderstanding, I´m going to edit the post. Apr 30 '21 at 8:32
• 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 Apr 30 '21 at 11:16