Sources we use
We rely on primary sources: government agencies (IRS, CFPB, U.S. Census Bureau, HMRC, Australian Taxation Office, Canada Revenue Agency), the official guides of Fannie Mae and Freddie Mac, platform help pages for platform fees, and university real-estate research centers. We do not use lender marketing, forums or social media as sources of fact. Rules of thumb such as the 1% rule are labeled as rules of thumb.
How calculators are checked
Every calculator uses published, standard formulas. The code is covered by automated tests that check known answers (for example, a $200,000 loan at 6% for 30 years has a monthly principal-and-interest payment of $1,199.10, and the IRS first-year depreciation rate for a rental placed in service in January is 3.485%). We show the formula next to each tool so anyone can verify the result by hand.
What we will not publish
- Investment recommendations, return promises or market forecasts.
- Paid placements, affiliate links or reviews written for a lender, broker or platform.
- Claims we cannot support with a source.
Updates and corrections
Each page shows the date it was last updated. When lending guidelines, tax rules, platform fees or official statistics change, we update the affected pages. If you find an error, tell us through the contact page and we will review it and correct it.