Resources — How to Measure
Door Measuring Guide
Get your door opening right, down to the quarter inch.
You don't need measurements in hand to call us and get started — our team can help you measure over the phone or in person. If you'd like to have your numbers ready ahead of time, this guide walks through exactly how to take them yourself.
Step 1
What shape is the top of your door?
Look at the very top of your existing door unit, above the door and any glass side panels. It's one of three shapes — pick the one that matches, and use the matching measuring steps below.
Flat top
A straight header across the top — the most common configuration, with or without side lites.
Flat top steps
Arch or round top
A curved header, from a gentle arch to a full half-circle over the door and sidelites.
Arch & round top steps
Elliptical or unique
A flatter, stretched curve or an irregular shape. Use the arch & round steps, then read our note below.
Arch & round top steps
Step 2 · Flat top
Measuring a flat top door
You'll need two measurements: the height and the width of the finished opening.
- 1
Hold your tape measure plumb — straight up and down. Measure from the finished floor to the inner edge of the trim at the top of the door.
This is your height.
- 2
Hold your tape measure level — parallel to the floor. Measure from the inner edge of the left trim to the inner edge of the right trim.
This is your width.
Step 2 · Arch or round top
Measuring an arch or round top door
Arched openings need one extra measurement — where the straight trim ends and the curve begins — in addition to the overall height and width.
- 1
Hold your tape measure plumb. Measure from the finished floor up to the point where the arch begins — the top of the straight side trim.
This is where the arch starts.
- 2
Still plumb, measure from the finished floor to the highest point of the arch — the inner edge of the trim at the very top of the curve.
This is your overall height.
- 3
Hold your tape measure level. Measure from the inner edge of the left trim to the inner edge of the right trim, at the widest point.
This is your width.
Have your numbers? Send them with your quote request.
Add your height, width and — for an arched opening — where the arch starts to the project notes of your free quote, and tell us they came from this guide. Not sure about a measurement? Our team can walk you through it over the phone or measure in person.
Disclaimer: This measuring guide is intended to help you determine the size of your door unit. Abby Iron Doors is not responsible for any dimensions. We recommend that your door installer verify all dimensions. Call us for further assistance.
Need a hand measuring?
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