What this planner does
Painting a room and replacing its floor start with the same measurements. This planner asks for them once and uses them for every material: wall and ceiling paint, primer, flooring, underlay and baseboard. The result is one shopping list with the packages to buy for each material, what will be left over and, if you enter prices, the cost.
Like the separate paint calculator and flooring calculator, it estimates quantities from your measurements and the numbers on the product labels. It does not assess the walls, the subfloor, damp, wiring, permits or structural questions, and it does not replace the manufacturer’s instructions.
Measure once
Each room needs its length and width (or its shape if it is L-shaped or made of several rectangles), the wall height and the openings: doors and windows with their width and height. From these the planner derives:
- Walls: perimeter × height, minus the openings
- Ceiling: the floor area
- Floor: the floor area, with doorways not subtracted
- Baseboard: the perimeter minus the width of each door
If you are not sure what to measure, start with how to measure a room.
Worked example in feet
This is the example the planner starts with: a room 12 × 10 ft with 8 ft walls, one 32 × 80 in door and one 36 × 48 in window. The wall paint covers an example 350 ft² per gallon per coat, with 2 coats and 1-gallon cans; every material has a 10% allowance.
- Areas: perimeter 2 × (12 + 10) = 44 ft; walls 44 × 8 = 352 ft², minus 17.78 ft² (door) and 12 ft² (window) = 322.22 ft²; floor 12 × 10 = 120 ft².
- Wall paint: 322.22 × 2 ÷ 350 = 1.84 gal; 2.03 gal with allowance, so 3 cans (3 gal), about 0.97 gal left. Just over 2 gallons still means a third can.
- Flooring, boxes of 20 ft²: 120 × 1.1 = 132 ft²; 132 ÷ 20 = 6.6, so 7 boxes (140 ft², 8 ft² left).
- Baseboard (if you add it), 8 ft lengths: 44 − 2.67 (door) = 41.33 ft; 45.47 ft with allowance; 5.68, so 6 lengths (48 ft, about 2.53 ft left).
Worked example in metric
A room 4.2 m × 3.5 m with 2.4 m walls, one door 0.8 m × 2.0 m and one window 1.2 m × 1.2 m. Every material has a 10% allowance. The paint uses an example 10 m²/L per coat, below the best-case figure many labels print, because real walls rarely reach it (see paint coverage and coats).
- Areas: perimeter 2 × (4.2 + 3.5) = 15.4 m; walls 15.4 × 2.4 = 36.96 m², minus 1.6 m² (door) and 1.44 m² (window) = 33.92 m²; floor and ceiling 4.2 × 3.5 = 14.7 m²; baseboard 15.4 − 0.8 = 14.6 m.
- Wall paint, 2 coats, 2.5 L cans: 33.92 × 2 ÷ 10 = 6.78 L; 7.46 L with allowance; 7.46 ÷ 2.5 = 2.98, so 3 cans (7.5 L), about 0.04 L left.
- Ceiling paint (a different color), 2 coats, 2.5 L cans: 14.7 × 2 ÷ 10 = 2.94 L; 3.23 L with allowance; 2 cans (5 L), about 1.77 L left. The two paints are not added together because they are different colors.
- Flooring, boxes of 2.2 m²: 14.7 × 1.1 = 16.17 m²; 16.17 ÷ 2.2 = 7.35, so 8 boxes (17.6 m², about 1.43 m² left).
- Baseboard, 2.4 m lengths: 14.6 × 1.1 = 16.06 m; 16.06 ÷ 2.4 = 6.69, so 7 lengths (16.8 m, about 0.74 m left).
Already bought, and changes later
Plans change after the first trip to the store. For each material you can enter how many packages you have already bought. The planner keeps that number and compares it with the current requirement.
Say you bought the 8 boxes of flooring in the metric example, then decide to lay them in a herringbone pattern and raise the allowance to 20%: 14.7 × 1.2 = 17.64 m², and 17.64 ÷ 2.2 = 8.02, so the requirement becomes 9 boxes and the list shows 1 still to buy. If you lower a requirement instead, the list shows how many packages are more than you now need, so you can decide whether to return them.
Sealing and filling gaps
In step 2, open Plan other materials and, under Sealant and filler, add your cartridge (the volume from its label), the bead shape and width, then choose for each room where it goes: along the top of the baseboard, around doors and windows, along tile edges when tiles are planned, or a length you type. The planner multiplies the bead length by its cross-section (a triangular fillet is half the square of its width) and rounds up to whole cartridges. Choose a sealant suited to the joint and the room, and follow the cartridge’s instructions.
Shopping list, print and files
- Shopping list: one row per material with the product, color, finish, package size, packages, already bought, still to buy and, where you entered a price, the total.
- Print or PDF: a printable plan with the rooms, measurements, every material with its coverage, coats and allowance, the quantities and a checklist to tick off at the store. Use Download PDF to save it as a file, or Print to print it.
- CSV: the shopping list as a file you can open in a spreadsheet.
- Backup (JSON): the whole project as a file. Opening it later adds it as a new project; it never overwrites one you already have.
Your data stays on your device
All calculations and files are made in your browser. Nothing you type is sent to a server. The project is only kept between visits if you tick Keep my projects on this device; turning it off deletes the stored projects from this browser. If you clear your browser data or switch devices, use the backup file.
For the details behind the numbers, see paint coverage and coats and how pack rounding works.