Ben Oliver

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Picture rail string length calculator

08 April 2024

This gadget calculates the length of string required to hang a picture off a picture rail at the desired height.

Picture Rail Picture Width Height

A picture rail?

You get these in older houses sometimes. They are a strip of wood or metal high up on the wall, usually in a shape that allows for a hook to attach to them. They are a cool way to hang pictures on the wall without putting nails everywhere.

There are a number of ways and systems available to use them, but I like this simple method using string in a triangle shape, where the knot meets in the middle behind the picture.

What is this page?

It’s a pain measuring the right length of string to get the picture at the right height, but thanks to Steve Pythagoras we can use maths to figure it out. If you remember school, we are measuring the perimeter of an isosceles triangle.

All you need to know is the distance between the two d-rings on the back of the picture frame, and the desired height of your picture (measured from the d-rings to the picture rail).