These are estimates
Every figure on Interest Bench is arithmetic applied to numbers you typed, under assumptions printed on the page that produced it. That is all it is.
An estimate is useful. It is not the same as the amount your lender will charge, your bank will pay, or a government agency will award. Where our figure and theirs disagree, theirs governs your money and ours does not.
This is not advice
Nothing here is financial, investment, tax, legal or accounting advice, and nothing here is a recommendation.
That is a design decision before it is a legal one. No page on this site tells you what to do, ranks two options, or names a best choice. Where there are two reasonable courses, both are computed and both are shown. We do not know your other debts, your savings, your tax position, your job security or your plans, and every one of those bears on what you should actually do.
We are not a bank, a lender, a broker, an adviser or a fiduciary, and no use of this site creates any professional relationship.
Where the numbers stop being reliable
Each calculating page has a section headed what this does not account for, and it is specific rather than boilerplate. These apply across the whole site:
- Rates are assumed to hold. Most US credit cards, HELOCs, ARMs and savings accounts carry variable rates. A fixed rate in a model is a simplification, and over a long term it is the largest one.
- Tax is excluded. Savings interest is generally taxable in the year credited; mortgage interest may be deductible. Neither is modelled.
- Inflation is excluded. Every figure is in today's dollars. Over a long horizon that matters more than most of the arithmetic.
- Fees are mostly excluded. Annual fees, late fees, penalty rates, early withdrawal penalties, origination and closing costs are noted where they dominate and are not otherwise counted.
- Mortgage figures are principal and interest only. Property tax, insurance, HOA dues and escrow are real money and are not included, so these will not match a full monthly statement.
- Rules change. Award amounts, statutory limits and lending caps are revised, sometimes annually. Each page carries the date its figures and sources were last checked.
Sources
Formulas here follow named public authorities, including the Consumer Financial Protection Bureau, Regulation Z, Regulation DD, the Homeowners Protection Act, HUD's HECM rules and the Internal Revenue Code. Those are cited on the pages that rely on them and collected on how we calculate.
Citing a source means we followed its method. It does not mean that agency has reviewed, endorsed or checked this site, and none of them has.
No warranty
This site is provided as it is. We do not warrant that any figure is accurate for your circumstances, that the site will be available, or that it is free of errors. To the fullest extent the law allows, we are not liable for any loss arising from use of it or reliance on anything on it.
We do work at this. Formulas are tested against examples worked out independently before the code was written, sources are named, and assumptions are printed next to the figures they govern. That is an effort and not a guarantee.
Tell us when we are wrong
If a figure here disagrees with your lender, your bank or your own working, say so. A specific disagreement with a number is the most useful thing anyone can send us, and it is worth more than any disclaimer on this page.
See also terms of use and privacy.