One room, one shopping list
Renovating a floor usually means visiting half a dozen separate calculators: one for screed, one for tiles, another for adhesive and grout, and a laminate calculator that knows nothing about the subfloor underneath. Each asks for the room dimensions again, each rounds differently, and none of them add up to the list you actually take to the builders’ merchant.
This calculator works the other way round. You describe the room once — a simple rectangle, an L- or U-shaped room walked wall by wall, or an area you already know — and every material is derived from that single geometry. The result is a shopping list in the packages you can buy: bags, boxes, packs, rolls and buckets, with the leftover for each line and an optional cost.
What it calculates
The list follows the order in which the work is done, so it doubles as a plan for the job:
- Preparation: primer or bonding agent, PE separating membrane, perimeter edge strip, waterproofing for wet areas.
- Screed: bagged dry mix, cement and sand site mix, ready-mix liquid screed or self-levelling compound — including floors that are not level.
- Finish: tiles of any size and pattern, or laminate, click vinyl, glue-down LVT and engineered wood.
- Fixing: tile adhesive with the right trowel notch, grout, flooring glue.
- Trims and accessories: skirting boards, corner pieces, door transition profiles, spacers and levelling clips.
How the numbers are worked out
quantity to buy = ⌈ area × rate × (1 + waste) ÷ package size ⌉
Every line starts from the net floor area: the sum of all sub-areas minus exclusions such as a kitchen island or shower tray. Each material then applies its own consumption rate and waste allowance, keeping full precision until the very end, when the quantity is rounded up once to whole packages. Tap the “i” next to any line to see the formula with your own numbers.
Worked example
- Room 4.0 × 3.0 m = 12.00 m², 50 mm sand-cement screed, 600 × 600 mm porcelain tiles with 2 mm joints.
- Screed: 12 m² × 50 mm × 2.0 kg/m²/mm × 1.05 = 1,260 kg → 51 bags of 25 kg.
- Tiles: 12 m² ÷ (0.602 m × 0.602 m) = 33.1 tiles; with 10% waste 37 tiles → 10 boxes of 4 (14.40 m²).
- Adhesive: 10 mm notch at 4.0 kg/m² × 12 m² × 1.10 = 52.8 kg → 3 bags of 25 kg. Grout: 1.47 kg → one 2 kg bag.
Uneven subfloors are the normal case
Most screed calculators assume the floor underneath is perfectly flat, which is rarely true in an older house. Here you can enter the minimum thickness at the highest point and the level difference to the lowest point, choose how the floor slopes, or type in a grid of heights measured with a laser level. The calculator works out the true average thickness, warns you if the thickest spot exceeds what the product allows, and suggests a two-layer build-up when the difference is too large for self-levelling compound alone.
Several rooms, rounded once
Add the hallway, kitchen and bathroom as separate rooms. Each room keeps its own list for reference, but the project list sums identical products before rounding. If the kitchen needs 2.3 boxes of a tile and the hallway 1.4 boxes, you buy 4 boxes, not 3 + 2 = 5.
When you are done, share the project as a link, download a CSV, copy a plain-text list for a supplier, or print it. Every export includes the assumptions — waste percentages, consumption rates and product presets — so anyone can check the numbers.
Frequently asked questions
Is the calculator free?
Yes. There is no account and no paywall, and every calculation runs in your browser, so nothing you enter is sent to a server.
How much waste should I allow?
The defaults are 10% for straight-laid tiles, 15% for diagonal and 18% for herringbone, plus 5% for rooms under 4 m² and 3% for tiles with an edge of 1200 mm or more. Laminate defaults to 7%. You can override every value.
Can I use feet and inches?
Yes. Switch the units to imperial in the project settings. Lengths accept fractions such as 5′ 6 1/2″, and results are shown in square feet, cubic yards and pounds.
Are the consumption rates accurate for my product?
The presets are typical values. Products differ, so check the data sheet on the bag or the manufacturer’s website and change the rate if needed.
Does it work for several rooms?
Yes. Add rooms in the geometry step. The project list combines identical products and rounds to packages once, which usually saves a box or a bag.