Exact answers for home projects

Quick, worked-out answers to the questions people ask before they buy materials: how much paint, how many boxes of flooring, how many tiles, which rough opening, how many wallpaper panels. Every answer uses the same rules as the free Roomveil tool, shows its working, and opens the tool with the measurements filled in. New answers are added every week.

How are these answers worked out?

Each answer uses the same rules as the Roomveil tool: about 375 ft² per gallon or 10 m² per litre of paint, 10% spare for flooring and tile, a rough opening ½ inch larger than a window and 2 by 2½ inches larger than an interior door, and the International Residential Code for drain slope.

Can I use my own measurements?

Yes. Every answer has an Open in Roomveil button that starts the free tool with those measurements already filled in. Change them to match your own room, add a photo if you like, and Roomveil works out the exact amount, in whichever units you measured in, without an account.

Is this a substitute for a professional?

No. These are planning figures based on common rules of thumb and code minimums. Product coverage, local building codes and site conditions vary, so check the label, the maker's instructions and your local building department, or ask a qualified tradesperson, before you buy or build anything.