Your DIY Project Starts Here
No more guessing. Calculate what you need in seconds.
Whether you're tiling the bathroom, painting the spare room, or laying a patio — we'll help you work out materials and quantities so you can get on with the fun part.
What are you working on?
Choose the calculator that matches your project. Each one gives you a detailed breakdown with no fuss.
Tile Calculator
Planning a new bathroom or kitchen splashback? Pop in your room size and tile dimensions, and we'll tell you how many tiles to buy — plus a little extra for those inevitable cuts.
- Walls, floors & splashbacks
- Includes wastage & grout
- Common UK tile sizes built in
Paint Calculator
Freshen up any room without the headache. Tell us your wall dimensions and we'll work out how many tins of paint you need — accounting for doors, windows, and the number of coats.
- Emulsion, primer & undercoat
- Deducts doors & windows
- Multi-coat calculations
Concrete Calculator
Laying a patio, setting fence posts, or pouring a shed base? We'll help you figure out exactly how much concrete, ballast, and cement you need.
- Slabs, footings & posts
- Ready-mix & site-mix options
- Bags or bulk — you choose
Simple as 1, 2, 3
No jargon. No confusion. Just straightforward answers.
Measure Up
Grab your tape measure and jot down the length and width (and height if needed). That’s the hardest part done!
Pop In the Numbers
Enter your measurements and pick your materials. We’ll handle the maths — including wastage, because things never go perfectly.
Get Your List
You’ll get a full breakdown with quantities and bag sizes. Take it straight to B&Q or your local supplier.
Try the Tile Calculator
Here's a quick demo with a 3m × 2m bathroom and 300 × 300mm tiles. Adjust the numbers and see the results update.
Room Details
Tell us about your space and we'll do the rest.
Total tiles needed
73
tiles (including 10% wastage)
Floor Area
6.0 m²
Tiles (no waste)
66
Extra for cuts
+7
Tile Adhesive
30 kg
1 × 20kg bag, 1 × 10kg bag
Grout
2.4 kg
1 × 2.5kg bag, 1 × 10kg bag
Your Shopping List
Tile Adhesive (20kg bag)
Flexible wall & floor adhesive
Tile Adhesive (10kg bag)
Flexible wall & floor adhesive
Grout (2.5kg bag)
Flexible wall & floor grout
Grout (10kg bag)
Flexible wall & floor grout
About How Much To Buy
How Much To Buyprovides free calculators for UK home improvement projects. Whether you're tiling a bathroom, painting a bedroom, or laying a concrete shed base, our calculators help you estimate the quantities you need — so you can buy the right amount first time.
All calculations use standard coverage rates from manufacturers like Dulux, Mapei, BAL, and Blue Circle. We include waste allowances and suggest suitable bag or tin sizes to help reduce waste.
These calculations are estimates based on standard manufacturer coverage rates. Actual quantities may vary depending on surface conditions, wastage, and application technique. Always verify quantities with your supplier before purchasing.