Measure wall length and height first
Record every relevant dimension in the same unit and separate irregular sections. Small measuring errors multiply across an entire project, so check each figure before adding a waste allowance.
Handle openings consistently
Measure large doors and windows, calculate their area and subtract them from the gross wall area. Leaving small openings in the total can provide a modest practical buffer.
Record separate surfaces
Ceilings, trim and feature walls often use different products. Keep their measurements separate rather than combining everything into one paint figure.
Practical checklist
- Sketch the room and write each measurement beside its wall.
- Use metres throughout to avoid unit mistakes.