How the guides are made
This page sets out the rules the guides and calculators are made by, so you can check the work instead of trusting it.
The arithmetic is printed
Every worked example is computed from the assumptions printed beside it, using the same arithmetic the calculator runs. If a figure cannot be followed, that is a fault, not a style.
Two rulebooks, kept apart
US and German rules differ on tax, retirement accounts and fund taxation. Where they do, the guide names both treatments rather than translating one into the other. The region switch in the top bar changes which version you are reading.
Dates on every guide
Every guide carries its publication date and, where it has been revised, the date it was last updated.
Sources
Where a rule, a tax rate or a threshold is cited, the guide ends with a sources section naming the primary document, usually a tax authority, a regulator or an index provider. Figures without a primary source are labelled as worked examples.
Independence
No ads, no sponsors, no affiliate links to funds or brokers. Nothing recommended on these pages is paid for. The membership funds the work.
Limits
Tax rates and rules change, and a guide can lag behind. For a decision, check the linked primary document. Everything here is education, not advice.