Free Online Calculators, Converters & Daily Tools

Simple, fast and private web tools with no signup required.

Eighty Apps is a collection of seven browser-based tools for everyday calculations, conversions, planning and exploration. Every tool works without an account, and calculator inputs and saved lists stay in your browser.

Choose a focused tool for percentages, tips, unit conversions, world time, grocery planning, mortgage estimates or an interactive journey through the ocean. Each page includes a practical guide that explains its inputs, formulas and limitations.

How to use this tool

  1. Choose a tool from the list below based on the task you want to complete.
  2. Enter values or list items directly in the browser; no registration is required.
  3. Review the result and the page guide for formulas, assumptions and worked examples.
  4. Return to this dashboard at any time to switch to another tool.

Frequently asked questions

Is Eighty Apps free?

Yes. All seven tools are free to use and do not require an account or subscription.

Where is my information stored?

Lists, calculation history and preferences are stored in local browser storage. Calculator inputs are not submitted to an Eighty Apps account or database.

Does it work on mobile devices?

Yes. The tools use responsive layouts designed for modern phones, tablets and desktop browsers.