Field Measurement Guide

Accurate measurements are the foundation of a correct order. Use this guide to measure rough openings, existing frames, and wall conditions before placing your door and frame order.

Measuring New Rough Openings

For new construction, measure the structural rough opening — the clear space between framing members before any finishes are applied.

  1. Measure the Width

    Measure the rough opening width at the top, middle, and bottom. Use the smallest measurement. The frame nominal width should match the door width — a 3’-0” door requires a 3’-0” nominal frame, which installs into a rough opening approximately 2” wider (varies by frame profile and wall type).

  2. Measure the Height

    Measure from the finished floor (or structural slab) to the underside of the structural header. For standard floor-to-floor heights, a 7’-0” door is most common. Confirm the rough opening provides at least 2” of clearance above the nominal frame height for header anchoring and leveling.

  3. Measure Wall Thickness (Frame Depth)

    Measure the total wall thickness from finished face to finished face — this determines the frame profile depth you need. Common wall thicknesses and corresponding frame depths: 4” stud wall = 4⁄7“ frame depth; 6” stud = 5⁄7“; 8” CMU = 7⁄7“ or 8⁄7“. Custom depths are available.

  4. Check for Plumb and Square

    Use a level to verify the rough opening is plumb on both jamb sides and level at the head. Measure diagonally corner-to-corner — both diagonal measurements should be equal within 1⁄8”. Document any out-of-square conditions before ordering, as frames can only be shimmed and adjusted within a limited range.

Measuring Existing Openings (Replacement & Retrofit)

For replacement or retrofit applications, you’re ordering an existing opening (adjustable) frame. Measure the existing frame’s clear opening — not the rough opening behind it.

  1. Measure Clear Opening Width

    Measure from the inside face of one jamb to the inside face of the opposite jamb (the clear opening). Measure at the top, middle, and bottom — record all three. The existing opening frame will be ordered to match this clear opening size.

  2. Measure Clear Opening Height

    Measure from the floor to the underside of the frame head stop (not the soffit). Record the measurement. If the existing frame has a raised threshold or floor closer housing, note the floor-to-rabbet height as well.

  3. Measure Overall Frame Dimensions

    Measure the existing frame’s overall outside dimensions — the total width and height of the frame face. This ensures the replacement frame will cover the existing rough opening without leaving gaps at the perimeter. Note the face width (typically 2”) and any applied stop dimensions.

  4. Photograph the Existing Frame

    Take clear photos of the frame profile, corner connections, and anchor points before removal. Note the existing frame manufacturer and any hardware that must be reused or matched. This information helps your HMF Express rep verify the correct replacement frame type and any special requirements.

What to Record Before Ordering

Opening & Wall Information

  • Clear opening width (at top, middle, bottom)
  • Clear opening height (floor to head)
  • Wall thickness (face to face)
  • Wall construction type (CMU, drywall, concrete)
  • Floor type (concrete slab, wood, raised)
  • Any out-of-square or out-of-plumb conditions

Door & Frame Details

  • Door hand (hinge location — left or right)
  • Door swing direction (in-swing or out-swing)
  • Fire rating requirement (if any)
  • Hardware to be installed (lock type, closer, exit device)
  • Existing hardware to match or reuse
  • Finish or paint requirements
Standard Frame Depth Reference
Wall Construction Typical Wall Thickness Frame Depth
3-5/8” Metal Stud + Drywall4-1/2”–4-7/8”4-7/8”
6” Metal Stud + Drywall5-7/8”–6-1/4”5-7/8”
8” CMU (standard)7-5/8”7-7/8”
8” CMU + Drywall Furring8-5/8”–9”8-7/8”
12” CMU11-5/8”Custom

Actual wall thickness varies by stud size, drywall thickness, and finish conditions. Always measure in field — do not rely on nominal dimensions alone.

Ready to place your order?

Share your field measurements with your HMF Express sales rep to get accurate pricing and a fast turnaround.

How to Order