Affiliate disclosure

The short version

Some links on this site may be affiliate links, meaning we could earn a commission if you click through and take a product. You never pay more as a result, and a commercial relationship never changes a calculator result.

Our rules

• Commercial placements are labelled, and outbound commercial links are marked as sponsored.
• No partner influences a formula, an assumption, a default value or the ordering of results.
• We do not invent partners. Where no genuine programme is connected, the placement says so plainly.
• Placements sit alongside results, never in place of them, and never inside the calculation itself.

Why this matters

Affiliate income is how free tools stay free, but it creates an obvious conflict of interest. Publishing the rule — money never touches the maths — is the only way that conflict can be managed honestly.