Room Construction Calculator
ARIES BUILDERS
Geoff’s room calculator
Your room measurements. A clear materials estimate.
01 Measure your room
Example room loaded — replace these measurements with yours.
Results also update as you type. Rectangular rooms only.
02 Painting & tiling
Use your room dimensions above for painting and renovation work.
Wall tiling runs around all four walls. Half height means half your room height. Skirting defaults to 150 mm.
Tiles are automatically excluded from wall painting. For doors and windows, deduct only the opening area within each finish: the painted part under paint deductions, the tiled part under wall tile deductions.
03 Set your allowances
Auto allowance: 2 rows up to 2.4 m, 3 up to 3.2 m, then 4. Confirm centres and nog rows against the project design.
04 Insulation
Use coverage from the product packaging to estimate packs. R-values are selection labels; check the required product and cavity fit for your job.
Allowances for one rectangular room, with one lined face to each wall. Painting and wall tiling use your entered deductions. Other material estimates have no deductions or extra framing for doors and windows. Confirm quantities, sheet layout and framing details on site.
Your room at a glance
Painting areas
| All walls — gross area | |
|---|---|
| Walls to paint — excluding tiles & deductions | |
| Ceiling to paint | |
| Ceiling edge / perimeter |
Surface areas only — no waste or coat multiplier. Ceiling assumes the whole rectangular ceiling.
Tile quantities
| Floor tile area | |
|---|---|
| Wall / skirting tile area | |
| Skirting run — gross perimeter | |
| Floor tiles to allow, with waste | |
| Wall / skirting tiles to allow, with waste | |
| Total tiles to allow, with waste |
Quantities are in m², not individual tiles. Waste uses the setting on the left. Round up to whole boxes using your supplier’s coverage; allow for tile size, pattern and cuts.
Wall framing
| Studs, base count | |
|---|---|
| Stud timber allowance | |
| Nog rows | |
| Nogs, base count | |
| Nog timber allowance | |
| Top + bottom plates | |
| Total wall timber |
Ceiling framing
| Battens, base count | |
|---|---|
| Batten timber allowance | |
| Perimeter ribbon allowance | |
| Total ceiling timber |
Battens run across the room width, spaced along its length. Excludes ceiling joists and structural design.
Sheets & trims
2400 × 1200 mm sheets · selected waste included
| Wall plasterboard | |
|---|---|
| Ceiling plasterboard | |
| Total plasterboard | |
| Plywood flooring | |
| Skirting | |
| Scotia |
Insulation allowance
Gross area plus selected waste. Framing is not deducted. Packs are rounded up separately for each surface.
How this estimate is calculated
- Painting uses the actual surface area without waste or extra coats. Wall painting excludes the selected gross tiling band, then paint deductions. Wall tile deductions reduce tiles only; they do not add that area back to painting. Ceiling edge is a linear metre measurement.
- Floor and ceiling = length × width. Wall area = perimeter × height. Areas shown exclude waste.
- Each of four walls has an end stud at both ends. Extra corner studs, junctions, lintels, bracing, fixings and opening details are excluded. Stud timber uses full room height as a conservative allowance, not a cut length.
- Stud bays are rounded up per wall. Each bay has one nog per row. Nog timber is a gross allowance using wall lengths before deductions for stud thickness.
- Plates allow one top and one bottom plate. Extra top plates are excluded. Ceiling ribbon and battens are separate allowances; verify the actual ceiling system.
- Waste applies to all timber lengths, sheet areas and insulation coverage. Base stud, nog and batten counts exclude waste. Timber totals combine linear metres, not sizes or grades.
- Sheet quantities are area estimates, rounded up separately for walls and ceiling. Sheet orientation, joints and offcut reuse may change the order.
- The nog-row bands and insulation selections are estimating choices, not a statement of building-code compliance. Confirm the project specification before purchasing.