Upgrading to a steel entry door is an exciting investment in security, durability, and curb appeal. But before placing your order, one of the most important steps is making sure your rough opening is measured correctly.
At PINKYS Iron Doors, all of our steel doors are built using net sizing, meaning the dimensions include the entire frame. To ensure a proper installation, your rough opening must be 1 inch wider and 1 inch taller than the door size you order.
Below is a helpful conversation between a homeowner and a PINKYS sales specialist walking through the measuring process step-by-step.
Q&A: Measuring Your Rough Opening for a Steel Door
Homeowner:
I’m ready to order my steel door, but I’m confused about how to measure. Do I measure the slab only?
PINKYS Sales Specialist:
Great question. At PINKYS, all sizing is net size, which includes the full door system — the steel frame and the door slab together. So you are measuring for the entire unit, not just the swinging portion of the door.
Homeowner:
What exactly is a rough opening?
PINKYS Sales Specialist:
The rough opening is the framed opening in your wall before the door is installed. It’s the structural space created by your framing lumber where the door unit will sit.
Homeowner:
How much bigger does my rough opening need to be?
PINKYS Sales Specialist:
Your rough opening must be 1 inch wider and 1 inch taller than the door size you’re ordering.
- If you order a 36” x 80” steel door,
- Your rough opening should be 37” wide x 81” high.
This extra inch allows room for proper leveling, shimming, and squaring during installation.
Homeowner:
Why do I need that extra inch?
PINKYS Sales Specialist:
That space is critical for installation flexibility. It allows the installer to adjust the unit perfectly plumb and level. Without that clearance, the door may bind, not seal correctly, or fail to operate smoothly.
Homeowner:
Do I measure from drywall to drywall?
PINKYS Sales Specialist:
No — you’ll want to measure from stud to stud. If there’s an existing door installed, you may need to remove interior casing to see the true structural opening. Measuring drywall to drywall can give you inaccurate numbers.
Homeowner:
What about height? Where exactly do I measure from?
PINKYS Sales Specialist:
Measure from the subfloor (or finished floor if already installed) up to the header at the top of the rough opening. Always verify whether flooring will be added later, as that can impact your final height clearance.
Homeowner:
Does this rule apply to double doors too?
PINKYS Sales Specialist:
Yes, absolutely. Whether it’s a single door or double door system, the same rule applies — your rough opening must be 1 inch wider and 1 inch taller than the net door size ordered.
- Ordering a 60” x 80” double door
- Rough opening should be 61” x 81”
Homeowner:
What if my rough opening is already framed and doesn’t match that exactly?
PINKYS Sales Specialist:
If your rough opening is slightly larger, that’s typically fine — installers can shim accordingly. If it’s smaller, the opening may need to be adjusted before installation. When in doubt, we recommend confirming measurements with your contractor before placing the order.
Final Thoughts
Accurate measuring is the foundation of a successful steel door installation. Remember:
- All PINKYS door sizes are net sizes (including frame)
- Rough opening must be +1 inch width and +1 inch height
- Measure from stud to stud, not drywall
- Account for flooring changes
Taking a few extra minutes to measure correctly ensures your steel door will install smoothly, operate properly, and perform beautifully for years to come.
If you have any questions before ordering, the team at PINKYS Iron Doors is always here to help guide you through the process.
