How to measure a door opening before ordering

Three numbers matter when you order a door: the opening width, the opening height and the wall thickness. They decide which leaf width to pick in the configurator and whether a standard frame is enough. Measure the opening in the wall itself — not the old door and not the old frame.

What to measure

1. Width. Measure in three places — top, middle and bottom. Use the smallest value in your order: openings are rarely perfectly rectangular.
2. Height. From the finished floor (or the future flooring, if it is not laid yet) to the top of the opening. Measure on the left and on the right, take the smaller value.
3. Wall thickness. Including the finish — plaster, tiles or paint. It determines the frame: a standard one covers 75–95 mm, an adjustable one 100–180 mm.

How to pick the leaf width

The opening should be about 8–10 cm wider than the leaf: 3–4 cm on each side for the frame and the installation foam. For a 2000 mm leaf, add about 5–7 cm to the height.

Opening width	Leaf
68–72 cm	60 cm
78–82 cm	70 cm
88–92 cm	80 cm
98–102 cm	90 cm

If the opening falls between two values, choose the smaller leaf — the architraves will cover the gap. A leaf that is too wide simply will not fit.

Common mistakes

• Measuring the old frame instead of the opening. Once the frame is removed, the opening is usually 5–8 cm wider.
• Forgetting the flooring. Parquet or tiles take 1.5–2 cm of height.
• Measuring the wall without the finish. With plaster and tiles a standard frame may no longer be enough.

If in doubt, send a photo and the dimensions to info@windoor.lt or call +370 633 33347 — we will check before production starts.