Terms of use

Use the estimates as a starting point.

These tools support informed questions; they do not replace advice based on your complete circumstances.

Last updated: 26 July 2026

General information only

Calculator OS provides general estimates. Nothing on the site is financial, tax, legal, accounting, employment or investment advice, and no professional or client relationship is created by using a calculator.

Check the assumptions

Every calculator states its formula, assumptions and limitations. You are responsible for checking that they fit your contract, working pattern, jurisdiction and intended decision. Obtain qualified advice where the consequences matter.

Availability and changes

Tools may be corrected, updated, replaced or withdrawn. Calculator versions are tested, but uninterrupted availability and suitability for a particular purpose are not guaranteed.

Acceptable use

Do not attempt to disrupt the site, bypass security controls, misrepresent calculator output or use automated access in a way that degrades service for other visitors.