This is an online scale ruler that can be calibrated to actual size with a scale ratio that can be set yourself. You can set the scale ratio according to your needs, e.g.. 1:4, 1:8, 1:12...etc. In order to get the most accurate measurement, we bly recommend that you calibrate the ruler first, and set the actual pixels per inch for your device.

• Calibrate the ruler to actual size.
• Set the scale ratio, for example "1:12"
• Black number is inches(in), red number is feet(ft.), blue number is yards(yd.).

1. The easiest way to figure your PPI is to visit this site. PDI Love. For example my monitor is 1920 x 1080 and is 25" diagonally with a PPI of 88.
2. The most accurate way is to simply use a real ruler against your screen and adjust the setting until the top of the ruler is exactly the same as your real ruler then click Save PPI.

If you would like calculate the scale length or real length, we have a scale calculator, it can help you quickly and easily calculate the scale length, your welcome to try it.