We have tried to design our app to give the best measurement possible, within the shortest amount of time possible. In order to do that, our App needs to use the paper as a reference point for scale.
Depending on where you are in the world, you may use different size of paper; in the US, the common standard is 8.5 x 11 inches (US LETTER), and in Europe and Asia the common standard is A4 which is 210 × 297 millimeters.

Did this answer your question?