About FPSPOT

These tools run calculations and random choices in your browser. Each page explains its input range and result rules.

Random choices use the browser cryptographic random source with rejection sampling. Decimal calculators use exact integer arithmetic where stated.

Calendar ages are not legal age determinations. Pet ages are rough source-based estimates. Financial outputs describe the entered figures, rather than predicting returns.

This site is built with Astro and a theme adapted from the MIT-licensed AnvilWiki project.

Questions about a tool, a correction, or a data point you want checked? Email hello@fpspot.com and include the page address you are writing about.