Finance Tools

Finance tools that compute the standard numbers you would otherwise build in a spreadsheet: loan and mortgage amortization, retirement projections with employer matching and inflation adjustment, APR back-calculated from fees, compound interest with arbitrary contribution patterns, payroll math, and the dozen smaller calculations that come up around buying a car, renting an apartment, or planning a budget. Every projection here uses standard time-value-of-money formulas with the assumptions stated on the tool page; there are no proprietary models or undisclosed fees baked into the numbers. The most common misconception is that an APR and an interest rate are the same thing. They are not: the APR reflects the true cost of borrowing including origination fees, points, and required insurance, and the difference between the two figures is exactly what the borrowing-cost tools here are designed to surface. A second common mistake is reading a 401(k) projection at face value without adjusting for inflation; the retirement projections here return both nominal and inflation-adjusted figures so the purchasing power of the final balance is visible alongside the headline number. If you are new to the category, start with the loan payment tools for any borrowing decision, the retirement projections before your next benefits enrollment, and the compound interest tools to understand how starting earlier with a smaller monthly contribution compares to starting later with a larger one. Tax estimates are general-purpose and not a substitute for a CPA.

18 tools available