A lot of financial calculators want something from you before they will answer a question. An email address, a phone number, an account. smartfin.fyi was built without that step. Work out compound interest, test a retirement plan, or check a loan payoff schedule, and the answer appears.
We host a growing collection of calculators for investing, retirement planning, and borrowing. Every tool is built for speed and mathematical accuracy. They are also available as clean embeddable widgets for publishers who want calculators on their own websites.
Our calculators produce mathematical outcomes based on your inputs and historical market data, and that is where they stop. Smartfin does not sell financial products, manage money, or provide financial, legal, or tax advice. A calculation is just information. It is not a personalized recommendation.
The calculators run locally on your device using client-side code. What you type into them stays inside your browser. The simulator is the exception: when you pick a company, that choice goes to our server to fetch its price history. If you upload a CSV file to the historical simulator, the data is processed locally and never sent to a server. There are no user accounts, no tracking profiles, and no saved inputs.
The simulator runs on historical S&P 500 daily closing prices compiled from standard market data feeds. These are refreshed daily and adjusted for stock splits and reinvested dividends.
A few limits worth knowing:
Have a calculator you wish existed or spotted a visual bug on the site? Reach out at contactus@smartfin.fyi