2024-12-28 5 min read
# Size Measurement Guide: What Every Homeowner Should Know
Whether you're replacing an old garage door or installing one on a new construction, getting the measurements right is critical. This guide will help you understand what measurements matter for a successful new door installation.
- Width: 8-10 feet (most common: 9 feet) - Height: 7-8 feet (most common: 7 feet)
- Width: 16-18 feet (most common: 16 feet) - Height: 7-8 feet (most common: 7 feet)
- Width: Up to 20 feet - Height: Up to 14 feet
Measure the inside of the opening at the widest point. Take measurements at the top, middle, and bottom—use the smallest measurement.
Measure from the floor to the top of the opening on both sides. Again, use the smaller measurement if they differ.
Measure from the top of the opening to the ceiling or any obstruction. Standard doors need at least 12 inches of headroom; low-headroom kits are available if you have less.
Measure from the opening to the wall on each side. Standard installation requires 3.75 inches minimum on each side.
This is the depth of your garage from the door opening. You'll need at least the door height plus 18 inches for the opener.
If your garage floor slopes, note the difference. We can compensate with specialized bottom seals.
Note any pipes, ductwork, or electrical panels near the opening. These may require special mounting or adjustments.
If replacing a door, measure the current door as well. Note the track type and spring system for accurate quoting.
While DIY measurement gives you a good estimate, professional measurement ensures precise fit, proper clearance, correct spring sizing, and code compliance — including fire safety requirements.
Garage Door Cornelius provides free on-site measurements and estimates for new door installations across Cornelius, Charlotte, Huntersville, and all service areas. Our experienced technicians will ensure your new door fits perfectly. Also check our budget-friendly options guide for cost-saving tips. Call (980) 944-8635 or contact us online to schedule.