How to Measure a Door？
Why Accurate Door Measurements Matter
Whether you're replacing an old door or installing a new one, accurate measurements are critical. A door that's too big won't fit; one that's too small leaves gaps that compromise insulation, security, and aesthetics.
Tools You Will Need
- Measuring tape (preferably metal)
- Pencil and paper
- Step ladder (for tall frames)
- Level (optional but recommended)
Step-by-Step Guide: How to Measure a Door
Step 1: Measure the Width
Measure the width of the door in three places: top, middle, and bottom. Record the smallest measurement.
Standard widths include: 28", 30", 32", 36".
Step 2: Measure the Height
Measure from the floor to the top edge of the door on both sides to ensure accuracy. Take the smaller value.
Standard height is typically 80" (6 ft 8 in).
Step 3: Check the Door Thickness
Use a measuring tape to check the thickness of the existing door panel. Interior doors are usually 1-3/8", while exterior doors are typically 1-3/4".
Step 4: Measure the Rough Opening
- Width: Measure between the framing studs (not trim).
- Height: Measure from the subfloor to the top of the rough opening.
- Wall depth: Important for prehung door frames.
Step 5: Determine Door Swing Direction
Stand on the outside of the door. Observe the hinge position:
- If the hinges are on the left and the door opens in – it’s a left-hand inswing.
- If the hinges are on the right and the door opens out – it’s a right-hand outswing.
Measurement Guidelines by Door Type
| Door Type | Measurement Focus |
|---|---|
| Prehung Doors | Rough opening: width, height, and wall depth |
| Slab Doors | Existing panel: width, height, and thickness |
| Double Doors | Total width + gap between leaves |
| French Doors | Same as double doors, symmetry is key |
Common Mistakes to Avoid
- Measuring only one spot on the door width
- Ignoring floor level differences
- Guessing standard sizes instead of measuring
- Missing the swing direction and door handing
Need Help or Custom Doors?
At Zonle Doors, we offer precision-fit doors tailored to your measurements. Whether you need WPC, wooden, steel, or aluminum glass doors — our experts are ready to help.
Click here to get a quote or book a consultation.