About blow.tools

blow.tools is a collection of free calculators for DIY and home improvement projects. The goal is simple: help you buy the right amount of material the first time – no sign-ups, no clutter, and support for both imperial and metric units.

The calculators use widely accepted rules of thumb for coverage, yields and waste allowances. They give a good estimate, but always check product labels and local building requirements before you start a project.

The site is free to use and may be supported by advertising and affiliate links. If you buy a product through a link on this site, we may earn a small commission at no extra cost to you.

Contact

Found a mistake or want a new calculator? Get in touch at [contact email coming soon].