Finance calculators

How to pick a wealth-building tool

Every finance calculator here shares one purpose: building wealth. If you're in the saving phase, the compound and simple calculators show the difference monthly contributions make; if you're investing, Stock DCA, dividends, and backtesting chart the long-run results of ETF accumulation and dividend reinvestment. If you're dealing with debt, the loan repayment calculator compares equal-payment and equal-principal methods; if you're planning retirement, the FIRE and 401(k) calculators check your target nest egg and the date you'd reach it.

Choosing a tool is straightforward — start from 'what do I want to do with my money right now?' Pick the tool that fits your situation among saving, investing, repaying, and retiring, then add the US federal income tax calculator if you want to see how your effective and marginal rates shape the outcome. Because the same inputs can diverge sharply between pre-tax, after-tax, and real value, it's more accurate to carry your numbers into related tools rather than stopping at just one.

What ultimately decides your wealth-building outcome is tax. 401(k) contribution rules, federal brackets, and FICA move your real return, and the US tax calculators here apply 2026 IRS figures by default; every simulator also shows inflation-adjusted real value alongside nominal results, helping you judge by what you actually keep rather than headline returns. All figures are for reference; your actual tax depends on individual circumstances.