Plan better, build with confidence.
Useful calculations and practical examples for planning improvements around your home.
Spaces
Dimensions, irregular layouts, furniture placement and clearance.
Explore guides →Walls
Paint, wallpaper, tiling and openings.
Explore guides →Floors
Floor area, tiles, boxes and cutting allowance.
Explore guides →Roofs
Roof geometry, pitch and material estimates.
Explore guides →Explore guides
How much paint do you need for a room?
Measure wall area, subtract openings when appropriate, and estimate coats, paint coverage and an allowance with a worked example.
Read guide ↗Roofs · GuidesHow to calculate the actual area of a sloped roof
Learn the difference between plan area and roof surface area, with a worked 30-degree example and material allowance.
Read guide ↗Spaces · GuidesHow to measure a room with irregular walls
Create a reliable sketch, measure recesses and openings, and transfer an irregular outline into a floor plan.
Read guide ↗Floors · GuidesHow to calculate floor tiles and boxes
Estimate the number of tiles and boxes from floor area, tile dimensions, cutting allowance and package quantities.
Read guide ↗Spaces · GuidesHow much clearance should you leave between furniture?
Plan comfortable circulation around beds, wardrobes, tables and doors without confusing estimates with accessibility rules.
Read guide ↗Walls · GuidesHow many wallpaper rolls do you need?
Calculate full strips per roll, allowances and pattern repeats rather than relying on wall area alone.
Read guide ↗Floors · GuidesHow to calculate the area of an L-shaped floor
Two reliable geometric methods to measure an L-shaped room and prepare for tile estimation.
Read guide ↗Roofs · GuidesFlat, mono-pitch, gable and hip roofs explained
Understand four common roof forms, how their slopes affect surface area and what to check before choosing materials.
Read guide ↗Case studies
Case study: tiles for an L-shaped kitchen
Calculate floor area, 60 × 60 cm tiles, an allowance and boxes for an L-shaped kitchen with a recessed corner.
Read case study ↗Spaces · Case studiesCase study: arranging a 3 × 4 m bedroom
Compare a bed, wardrobe and side table in a 12 m² bedroom, including circulation and usable space.
Read case study ↗Walls · Case studiesCase study: painting a 4 × 3 m room
Calculate net wall area and litres of paint for a room with one window and one door.
Read case study ↗