Size Measurement Guide: What Every Homeowner Should Know

January 5, 2026

<p>Accurate measurements are crucial when ordering a new garage door. An improperly sized door can result in security gaps, weather infiltration, and improper operation. This guide will help you gather the measurements professionals need to quote your project accurately.</p> <h2>Width Measurement</h2> <p>Measure the width of the opening at its widest point, typically at floor level. Take measurements at the top, middle, and bottom of the opening. Use the largest measurement. Standard residential widths are 8, 9, 10, 12, 16, and 18 feet, but custom sizes are available.</p> <h2>Height Measurement</h2> <p>Measure from the floor to the top of the opening on both sides. Again, use the larger measurement if they differ. Standard heights are 7 and 8 feet, with 7 feet being most common for single-car garages.</p> <h2>Side Room and Headroom</h2> <p>Side room is the space between the door opening and the nearest wall or obstruction on each side. Most standard systems require 3.75 to 4 inches minimum. Measure both sides separately.</p> <p>Headroom is the distance from the top of the door opening to the ceiling or nearest obstruction. Standard torsion spring systems need 10-12 inches of headroom. Low-headroom options are available for tighter spaces.</p> <h2>Backroom Depth</h2> <p>This is how far back the garage extends from the door opening. The track system needs to extend into this space when the door is open. Measure from the opening to the back wall. Most residential doors need depth equal to the door height plus 18 inches.</p> <h2>Special Considerations</h2> <p>Note any obstructions like water heaters, HVAC units, or storage shelves. Check for electrical outlets, light fixtures, and switches that might interfere with installation. Take photos to share with your installer.</p>

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