If you are doing home remodeling and want to replace your existing door, when ordering doors online, it is important to get a basic idea of your door rough opening. Read this article and write down the following measurements. They will help you to select the correct size that will guarantee the best fit. Please make sure that the rough opening is at least about 1-1/2” wider than the frame size/ unit size and about 1” taller. For example, your door rough opening is 82” high and 73-1/2” wide, then the door size would be 81 high and 72 wide.

Rough Opening Measuring Guide

Watch this video to learn how to measure for a new pre-hung iron front door.
Measuring the rough opening perfectly is helpful for you to purchase the right door size.

Drop element here

How Our Doors Are Measured

Our doors are pre-hung doors that are easy to install. The size of our door is called net frame size or unit size. It is a whole door system that consists of a header jamb, side jambs, and a threshold. Its width is measured from the outside of the left jamb to the outside of the right jamb. Its height is measured from the bottom of the threshold nose to the top edge of the header jamb.

What Is The IWD Iron Wrought Doors' Size

When you order a door from IWD Iron Wrought Doors, please pay attention to the measurement. Here is a drawing for example, it is a 64"Wx84"H size iron double door. It points out the overall size of a completed door system. The height is including header jamb and threshold; the width is including both sides' frames (both jambs' thickness). Please advise your whole door system size to IWD for a quote.

A Completed Iron Door System Drawing

Measure The Sizes For An Iron Door

Door Slab Size <<

The door slab is the actual operating door that does not include any frame. Its width is measured from the inside of the left jamb to the inside of the right jamb. Its height is measured from the bottom of the sill to the inside of the head jamb.

>> Rough Opening Size

Getting the rough opening size is the quickest way to ensure the proper fit of the door unit. The Rough Opening is a structure of framed wall that surrounds the door unit and it is measured from studs to studs. An accurate rough opening requires you to remove the interior or exterior casing and measure. The Rough Opening is typically about 1-1/2” wider than the frame size/ unit size and about a 1” taller.

Brick Opening Size <<

The Brick Opening size of the entry door is measured from the exterior side of the house from Brick to Brick.

>> Confirm Your Jamb Size <<

It is the measurement of the wall thickness that the door unit will be fitting into, this includes any sheetrock or sheathing/siding that is on the outside as well. If the wall thickness is 6" including drywall, we will suggest 6" jamb size for you. 4-9/16", 6” and 6-9/16" are the three most choose standard jamb sizes in our shop. We can also customize it for you.

Cross Section Of Door Frame

>> Follow our tips to accurately measure an arched door

1. Remove the Trim 

Accurate measurement of the rough opening requires you to remove the interior molding and measure it from the inside of your home.

2. Measure the Width

Measure the top, middle and bottom width of the door frame. Use the shortest measurement when ordering if you get different dimensions.

3. Measure the Height

Measured from the floor surface or the bottom of the threshold to the peak of the door arch in the center.

4. Measure The Spring Line Height

Measured from the floor surface to the spring point at which the arch begins to curve.

5. Calculate the Arch Height

Write down the arch height; The height of arch = the door frame height(H1) - the spring line height(H2)

Choose The Appropriate Size For Your Barn Door

Barn Door Size Example 

84” Tall Opening

Height Size: 84”+2”=86” Your barn door height should be 86” tall.

36” Wide Door  

Track Size: 36”+36”-2.36”=69.64” Your barn door track should be 69.64” long. 

Make sure you have enough wall space on the side of the opening for the door to open completely.

34” Wide Opening

1: Width Size: 34”+2”=36” Your barn door should be 36” wide if your door is against the wall. 

2: Width Size: 34”+4”=38” If your door is in the middle and covers the opening, then your barn door should be 38” wide.