CSS Web Ruler

Assuming your browser and graphical system (Windows®, X11, whatever) are configured with the correct physical size (DPI) this should be accurate.

This box should be precisely 1 inch in height and width. if you can't see this as a box with a black border, this page probably won't work for you.

Metric

English

Custom

Width:
Unit: (valid CSS units are: in, cm, px, em, ex, pt, pc)
Scale: (number of minor tics per unit)