How to measure a room for a floor plan
A practical measuring order, a worked wall example and a checklist for doors, windows and furniture.
Measure between the finished inside faces of the walls. Record each wall first, then locate its doors and windows from the same corner. For furniture, use the full outer dimensions, including arms, handles and projections.
1. Sketch the room before measuring
You need a tape measure or a laser measure used according to its instructions, a way to record numbers and access to the wall corners. Draw a rough outline on paper. Label the corners A, B, C and D, and add any alcove, chimney breast or bay. Your sketch does not need to be to scale yet.
Draw door swings and mark windows. Write the units at the top of the page and keep them consistent: 4,250 mm is 425 cm or 4.25 m. Mixing units is an easy way to create a room that looks plausible but is the wrong size.
2. Measure the outline, including recesses
- Work around the room in order. Record the length of every wall section between corners.
- For an alcove or chimney breast, measure both its width and how far it projects or recedes. A single overall width will hide that change in the floor outline.
- Measure opposite walls separately. Do not assume they match.
- Use diagonal measurements as an additional check where possible. Matching diagonals alone do not prove that every corner is square; investigate any disagreement with your wall measurements.
- Record ceiling height and the position and height of beams or slopes if they affect furniture. A floor plan by itself will not show these restrictions.
3. Locate each door and window from a fixed corner
For each opening, record the distance from the chosen corner to the opening, the opening width and the remaining wall. Note whether you measured to the frame or trim, and include protruding trim when checking furniture. Add the hinge side and swing direction for doors. For windows, record sill height if a desk, sofa or radiator could sit underneath.
A worked wall check
In this example, 600 mm of wall + a 1,000 mm window + 2,400 mm of wall = 4,000 mm overall. If your parts do not add up to your overall measurement, remeasure before drawing. Do not stretch the window or move a corner just to make the numbers agree.
4. Record the things furniture must work around
Mark radiators and their projections, skirting boards, sockets, access panels and fixed storage. Measure furniture at its widest and deepest points. Record extra space needed when a drawer, cupboard door, sofa bed or recliner is open, using the actual product information.
Check where people enter and move through the room. An empty gap on a drawing can disappear when a door opens or a chair is pulled back.
Your room measurement checklist
| Record | Include |
|---|---|
| Room outline | Every wall section, opposite walls, recesses and projections |
| Cross-checks | Overall dimensions, opening chains and diagonals where useful |
| Doors | Corner offset, frame and trim, hinge side, swing and opening height |
| Windows | Corner offset, width, sill height and opening movement |
| Fixed features | Radiators, sockets, storage, beams and sloping ceilings |
| Furniture | Outer width, depth and height, plus space needed in use |
You can print this page and take the checklist around the room. For another practical reference, IKEA’s room measurement checklist also covers room dimensions and the position of openings and outlets.
5. Turn the measurements into a plan
Enter the inside width and depth for a rectangular room, then position the openings and furniture. Compare the drawing with your sketch before trying new arrangements.
Common measuring questions
Should I use inside or outside dimensions?
Use finished inside dimensions when deciding whether furniture fits. Outside dimensions include wall thickness and will overstate the space available indoors.
What if the room is L-shaped?
Record every segment of the L. The rectangle enclosing the whole room includes space outside the usable floor; it is not a substitute for the actual outline.
Can I start from an estate agent’s floor plan?
Use it as a starting reference. Check the dimensions in the room and calibrate an imported drawing against a known measurement. A scaled image cannot correct an inaccurate original plan.