Door Measuring Resources

Measure for Prehung Interior & Exterior Doors

Use Nick's printable forms, diagrams, and installation videos to help confirm rough openings, masonry openings, and replacement door measurements before ordering.

Interactive Measuring Tool

Door Size Calculator

Select your door setup to calculate the Unit Size, Rough Opening, Brickmold Size, and Masonry Opening. Results update automatically as you make changes.

Build the Opening Visually

Use this tool as a guide before filling out the measuring form or calling Nick's for help with your project.

Single Door 36" × 6'-8" No Sidelights

Choose Your Door Configuration

Choose the width of the individual door slab.
Venting sidelight options require a 14" or larger sidelight width for lock mechanism clearance.

Your Calculated Sizes

Unit Size

Overall outside dimension of the prehung door unit.

Rough Opening

Framed opening size with room for shimming and adjustment.

Brickmold Size

Approximate outside dimension including brickmold trim.

Masonry Opening

Important when brick, stone, stucco, siding, or trim surrounds the door.

Email Measurements

Calculator results are based on Nick's standard prehung door sizing rules. Custom units, special jambs, installation conditions, or field conditions may vary. Always confirm final sizing before ordering.

Still not sure?

Send photos of the existing opening along with your measurements and a Nick's door specialist can help review the details.

Send Photos / Measurements

Door Measuring Forms

Review the measuring guide first, then choose the correct door schedule form or contact your Nick's sales representative for help.

Step 2: Download a Door Schedule Form

Use these printable forms to record door sizes, swing direction, jamb details, quantities, and notes for your order.

Step 3: Send Your Measurements

Email one of our sales representative with your measurements, photos, and any project notes.

Watch & Learn

Measuring and Installation Videos

Review the videos below before measuring or installing your door. These are especially helpful for confirming proper installation technique.

How to Measure and Install

Overview video for understanding the measuring and installation process.

Installing an Exterior Door

Installation video for exterior door projects and replacement entry doors.

Important: Confirm the Rough Opening and Masonry Opening

It is vital to get the rough opening measurement correct. You typically need approximately 1" of play and shim room when installing a prehung door. When measuring for a replacement door, also get the masonry opening measurement if there is existing brick, stone, stucco, wood siding, or vinyl siding around the entry door, because the surrounding material can affect proper fitment and installation.

Helpful Buying Resource

Not Sure What Size Door You Need?

Download our free Door Size Guide with standard door sizes, rough opening dimensions, and measuring tips used by homeowners, builders, and contractors.

Helpful Links

Parts, Door Sweeps, and Installer Resources

Need parts, installation help, or finishing guidance? Use these resources to continue planning your project.

Order Replacement Parts

Find common replacement parts for Nick's doors.

View Parts

Installing a Door Sweep

Review finishing and maintenance tips, including door sweep installation guidance.

View Door Tips

Find a Door Installer

Looking for project help? Visit the installer resource page for preferred installers and trade partners.

Find an Installer

Not Sure Which Measurement Matters?

Start with the printable forms, then compare your opening to the diagrams and videos before finalizing your order details.

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