Every Formula Factory calculator, organized by category. Choose a category to search and explore its tools — all free, no signup required.
How to find the right calculator
Formula Factory brings together free calculators for engineering, lighting, CNC machining, fabrication, DIY and construction, automotive, cooking, coffee and tea, yarn and fabric, and everyday math. Pick the category closest to your project, then use the search box to narrow the list to the tool you need.
Most calculators come with a plain explanation of the formula, a worked example, and notes on common mistakes. Reference charts and guides sit alongside them, so you can look up standard sizes, properties, and ratings and learn how a result is worked out.
Results are estimates meant for planning and learning. Always check important numbers against manufacturer data, local codes, and a qualified professional, especially for anything structural, electrical, or safety related.