How to Measure a Television Picture Size

Measure television screens on the diagonal.

Someone measuring a rectangle will measure the height, width or the perimeter, so those are the dimensions you might think to use to measure a television picture size. However, in this case the traditional thinking is wrong. A television screen is measured on the diagonal. The diagonal is used because it lets consumers compare television sets based on screen area no matter how the screen is shaped.

Things You'll Need

• Tape measure or yardstick

Instructions

1. 

   Use a yardstick or tape measure to measure a TV screen.

   Position the tape measure with the starting point at the top left corner of the television screen, and hold the end of the tape.

2. Pull the tape measure down and across the screen to the lower right corner.

3. Look at the number on the tape measure. This is the size of your television picture screen.

Tips & Warnings

• Some television manufacturers would specify both viewable area and screen size on older televisions.

References

• Gadget Toad: TV Measurements
• Math Forum: When would I use the Pythagorean theorem?