Not very accurate

This is a novel idea and it seems like a good one. It says my door frame is 2 feet 6 inches but I am certain that is not anywhere near the correct measurement for a standard door frame. When I tried calibrating it tells me to stand exactly 9 feet 10 inches from whatever I want to calibrate with and pick a spot on the ground. Each time there is an error and it probably means that I am not exactly 9 feet 10 inches away. I have never experienced these types of problems with an actual tape measure.

Sodaguy about Measure Tape