About Calculator Porch
Calculator Porch is a free collection of online calculators for math, statistics, everyday life, construction, finance, energy & solar and pets, with more added as they're built and tested. Browse them all on the A–Z list.
Who builds it
Calculator Porch is written and maintained by Ahsan Khan, who builds every calculator, formula and explanation on the site and reviews each page before it's published and whenever its data is refreshed.
How the calculators are built
- Each tool uses a published formula, shown on its page with a worked example you can check by hand.
- Prices, rates and constants come from cited sources, listed with the date they were checked.
- The same code runs in your browser and in an automated test suite that runs on every update.
- Nothing you type is sent anywhere: calculations happen in your browser.
The full detail is on the methodology page. Results are estimates to help you plan, not professional, financial, legal or veterinary advice.
Contact
Questions, corrections or suggestions for a new calculator: contact@calculatorporch.com.
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