Calcupine is a set of free calculators for home projects: paint, drywall, wallpaper, flooring, tile, concrete, pavers, mulch, sod, fences, decks, roofs and stairs. Each one answers the question you have standing in the store aisle: how much do I actually need to buy?
Why we built it
Most material calculators stop at square footage. Real projects have L-shaped rooms, doors and windows, waste from cuts, and products sold in boxes, bags and gallons. Buying too little means a second trip mid-job; buying too much wastes money on materials you may not be able to return.
So every calculator here handles odd shapes, adds the extra the trades plan for, rounds to the units the store actually sells, and gives you a shopping list you can print or copy to your phone.
How we keep the numbers right
- Every formula is published on our How we calculate page, with the assumptions behind it.
- Coverage figures, such as bag yields and paint coverage, come from typical manufacturer labels, and you can change them to match the product you buy.
- Each calculator is checked against worked examples before it goes live.
- If you spot a mistake, tell us through the contact page and we will fix it.
Who runs it
Calcupine is an independent site run by Abdullah. It is not owned by, or paid by, any store or manufacturer. The site is supported by advertising, which keeps the calculators free.
A note on safety and codes
Our results are estimates for planning and shopping. They do not replace product instructions, local building codes or advice from a licensed contractor, especially for structural work such as footings and load-bearing slabs.