Advertising and funding
This website uses Google AdSense to support its free calculators and guides. Ad availability varies by visitor and page.
Reviewed 29 October 2026
How advertising works
Google selects and delivers ads under its advertising policies, your location and your privacy choices. An advertisement is not our recommendation or an endorsement of the advertiser. Advertising does not change the calculator formulas.
Clear separation
Ads should be distinguishable from calculators, results and navigation. You do not need to click ads to use or support this site. If an ad interferes with a calculator, report the page to [email protected].
Other commercial relationships
We do not currently use affiliate links or paid sponsored articles. Any future commercial relationships will be disclosed alongside the relevant content.
Privacy and choices
Read our privacy notice, cookie information and privacy choices. You can also review Google’s partner-site privacy explanation and Google advertising choices.