About BuildMath Pro
BuildMath Pro is a set of free calculators for home and garden projects: concrete, gravel, mulch, topsoil, paint, drywall, tile, flooring, room area and air-conditioner size. The goal is simple: help you buy the right amount of material the first time, so you don’t run short halfway through a job or pay for pallets you don’t need.
Who builds it
BuildMath Pro is built and maintained by Shubham Dambale, a software developer. Material calculators are a natural fit for a developer: the maths is straightforward, but most calculators online stop at a raw volume and leave you to work out bags, boxes, cans and waste yourself. This site does that last step for you, in feet or metres.
How the calculators are built and checked
- Standard formulas, shown on the page. Each calculator explains the formula it uses and includes a worked example, so you can check the result by hand.
- Automated tests. The maths behind all 10 calculators is covered by automated tests against hand-worked examples, including unit conversions and edge cases such as an exact cubic yard of concrete.
- Published product figures. Bag yields, sheet sizes and paint coverage use the figures printed on common products. Where products vary (for example the weight of gravel or topsoil), the page says so and lets you enter your supplier’s figure.
- Recognised guidance. Air-conditioner sizing follows the ENERGY STAR room sizing chart and its standard adjustments.
- Private by design. Every calculation runs in your browser. The measurements you enter are not sent to or stored on our servers.
Limits
Results are estimates for planning and buying materials. Real projects vary with site conditions, products and how materials are installed. For structural work, or anything covered by building codes, check with a qualified professional and your local authority. See our disclaimer for details.
Corrections and suggestions
Spotted a mistake, or want a calculator we don’t have yet? Email hello@buildmathpro.com. Corrections are fixed quickly, and each calculator page shows when it was last reviewed.