How should the proportion of 3D parts be?

[overlok]

Hi,
I have 3D printers and I want to print parts. i open files with Cura but they are looks very small. What should i do?
For example:

[spierce]

Hello,

The parts were drawn in Imperial Units (Inches) and most 3D printers use the Metric System (mm). The parts will need to be scaled to 2540% or 25.4 times the size you're seeing in CURA.

Thanks,
Scott Pierce