About ToolLantern

ToolLantern is a growing collection of free calculators and utilities for questions that come up every day — pricing a product, buying tiles, estimating an electricity bill or tidying a JSON file.

How tools are built

Every calculator states its formula and can show its working, so you can check the result rather than trust a black box. Calculation logic is covered by automated tests that run before each release.

Where a figure depends on something that changes — payment processor fees, material densities, typical appliance wattages — the default is editable and the page says where to find the current value.

Your privacy

Developer and text tools process everything in your browser. Nothing you paste is sent to our servers. See the privacy policy for details on analytics.

Found a mistake?

Accuracy matters to us. If a result looks wrong, email contact@uzair.tech with the tool name and the values you entered.