Measuring for Garage Doors



  1. Measure Existing Door Width and Height in Feet and Inches: This determines the size of door needed. The finished opening should be the same size as the door depending on the type of door to be installed. Please consult Northgate Company to find out what finish size will work best for your application..
  2. Measure for Sideroom: 4″ is required on each side for installation of the vertical track for standard torsion springs.
  3. Measure Area Labeled “Headroom”: Distance between the top of the door opening (“jamb header”) and the ceiling (or floor joist). 12″ is required for standard installation of torsion springs. 15″ to 18″ of headroom is required for Carriage House doors. If you have restricted headroom, special “Low Headroom” hardware is available which will reduce the required distance to a minimal 4-1/2″.
  4. Measure area labeled “Backroom”: Distance is measured from the garage door opening toward the back wall of the garage.

Common garage door sizes include 8′ wide x 7′ high, 9′ wide x 7′ high and 16′ wide x 7′ high.

NOTE: If you will be installing a garage door opener, add an extra 2″ to the headroom measurement to account for opener unit size.