The numbers behind every investment decision.

Investment Calculators offers 18 free, interactive calculators across four categories: Investment (compound interest, investment growth, DCA, DRIP, CAGR, Rule of 72, lump sum vs DCA), Retirement (FIRE number, Coast FIRE, 401(k) growth, Roth vs Traditional IRA, safe withdrawal rate), Crypto (profit/loss with fees, crypto DCA, staking rewards, impermanent loss), and Tax & Planning (federal + state capital gains tax, net worth tracker). Every calculator updates in real-time as you type and includes detailed charts, methodology, and educational content.

Yes. Every calculator on the site is free to use with no paywalls or hidden fees. You get full access to all 18 calculators, interactive charts, detailed methodology, educational content, and both light and dark modes. We may introduce optional enhancements in the future, but the core calculators will remain freely available.

No. Every calculation runs entirely in your browser using client-side JavaScript. We do not send your inputs, amounts, or any financial details to any server. There is no backend database, no account system, and no cloud storage. Only anonymous aggregate analytics (pageviews and device type) are collected to help us improve the site.

Every calculator is built on standard, peer-reviewed financial formulas. The compound interest calculator uses A = P(1 + r/n)^(nt); the Rule of 72 is benchmarked against ln(2)/ln(1 + r); capital gains tax uses current-year IRS brackets (Rev. Proc. 2024-40); CAGR uses (End/Start)^(1/years) − 1. Formulas are documented in the methodology section of each calculator, and results have been verified against manual calculations and independent tools.

Our DCA Calculator simulates investing a fixed amount on a recurring schedule (weekly, biweekly, monthly, quarterly) at a constant assumed return. Our Lump Sum vs DCA Calculator explicitly compares deploying a single amount at time zero against spreading that same amount over a window. Lump sum typically wins in rising markets because every dollar is invested for longer; DCA reduces timing risk in volatile periods. Both calculators show year-by-year projections you can compare.

Our Capital Gains Tax Calculator handles any investment sold for a gain or loss, including cryptocurrency. The IRS treats crypto as property, so the same short-term (held <1 year, ordinary income rates) and long-term (held ≥1 year, preferential capital gains rates) rules apply. For multi-transaction crypto tracking, the site also offers a Crypto DCA calculator for cost-basis monitoring and a Crypto Profit/Loss calculator with exchange fee modeling.

For equity-heavy long-term projections, 7% real (inflation-adjusted) or 10% nominal is a common reference derived from the S&P 500's multi-decade history. For balanced 60/40 portfolios, use 4–5% real. For bond-heavy portfolios, use 2–3% real. For retirement withdrawal modelling, always prefer real returns so the numbers stay comparable to today's dollar costs. Remember: historical averages are illustrative only — actual returns vary significantly year to year.

Yes. Every page supports a polished dark mode that is toggleable from the header and persists across visits via localStorage. The site also respects your system-level prefers-color-scheme setting by default. Charts, inputs, and typography are all tuned for high contrast and readability in both themes.