Last updated: September 29, 2026.
Calculator inputs
Calculator inputs are generally processed in your browser and are not sent to a custom Useful Math Tools server for calculation. You do not need an account.
Information saved on this device
If your browser permits local storage, the site may save calculator IDs for favorites and recently used tools, concise calculation-history entries, shareable calculation links, and your history preference. This information is not encrypted and remains in the browser profile on this device unless you clear it.
The local storage keys are umt:favorites, umt:recentTools, umt:calculationHistory, and umt:settings, and, only when budget saving is enabled, umt:householdBudget. Saved budget values remain in this browser and can be cleared from the budget calculator or privacy page. No hidden user identifier is stored.
Hosting and technical data
The website is delivered through hosting and network infrastructure, including Cloudflare. Those providers may process ordinary technical information such as IP addresses, browser details, requested pages, timestamps, and security signals to deliver and protect the site.
Analytics and advertising
The site does not currently include custom analytics or advertising scripts. If these services are added, this policy will be updated to explain what is used and what choices are available.
Questions and updates
This policy may be revised as the site changes. The updated date above will show when the wording was last changed.