Built for US investors managing 401(k), Roth IRA, traditional IRA, HSA, 529 plans, taxable brokerage, and FIRE strategies.

Compound Interest Professional calculates compound growth, investment returns, savings goals, retirement projections, and withdrawal strategies—with high-precision charts and period-by-period tables. Estimate future value, required monthly contributions, target CAGR, time to reach your goal, and safe withdrawal amounts for every stage of your financial life.

◆ Core Features
● Future Value & Compound Growth
Enter initial principal, monthly contributions, expected annual return, and time horizon.
Project the future value of your 401(k), Roth IRA, traditional IRA, HSA, 529 plan, taxable brokerage, HYSA, or CD ladder—for any portfolio of stocks, ETFs, and index funds (SP500, NASDAQ 100, total market index).

● Monthly Contribution Calculator
Set a target amount—FIRE number, retirement nest egg, college tuition, or down payment—and find the exact monthly contribution to reach it.
Perfect for 401(k) deferral planning, Roth IRA monthly contributions, HSA funding, 529 college savings, and dollar-cost averaging (DCA) strategies.

● Withdrawal & Retirement Simulation
Model how long your portfolio lasts at a given withdrawal rate, or calculate the safe monthly amount you can withdraw without running out.
Useful for the 4% rule, Trinity Study analysis, sequence-of-returns risk planning, Roth conversion ladders, 72(t) SEPP early withdrawals, and bridge-period strategies before Social Security or RMDs (age 73 under SECURE Act 2.0).

● Time Needed to Reach Your Goal
Based on your returns and contributions, calculate how many years until you hit your FIRE number, $1M milestone, mortgage payoff date, or 529 college funding target.

● Required Return (CAGR)
Enter your goal, time horizon, and monthly contributions to calculate the CAGR your 401(k), Roth IRA, or taxable brokerage needs to hit your number.

◆ Visual Charts & High-Precision Modeling
● High-precision fixed-decimal calculations (no floating-point drift)
● Detailed amortization-style tables for every period

◆ Who Is This For?
● Long-term investors in 401(k), Roth IRA, traditional IRA, taxable brokerage, ETFs, and index funds (SP500, VTSAX, QQQ)
● HSA maximizers using triple-tax-advantaged accounts as a stealth IRA for retirement healthcare
● Parents funding 529 plans, Coverdell ESAs, or UTMA accounts for college savings
● FIRE followers planning lean FIRE, fat FIRE, coast FIRE, or barista FIRE
● Mortgage payoff planners comparing extra principal payments vs investing in the market
● Retirees modeling the 4% rule, Trinity Study withdrawals, Roth conversion ladders, or 72(t) SEPP early withdrawals
● Anyone navigating SECURE Act 2.0 changes (RMD age 73, 529-to-Roth rollover, expanded catch-up contributions)
● Students and professionals learning compounding, APY, APR, CAGR, and time-value-of-money concepts

◆ Example Scenarios
"If I contribute $2,000/month to my 401(k) including employer match for 30 years at 8%, how much will I have at 65?"
"Can I retire at 55 with $1.2M split between my Roth IRA and taxable brokerage, withdrawing $4,000/month?"
"How much should I add to my HSA each year to reach $500,000 by age 65?"
"If I pay an extra $500/month on my 30-year mortgage at 6.5%, how many years and how much interest do I save?"
"What CAGR do I need in my Roth IRA to hit $1M by age 50 with $600/month

◆ Notes
This app is for educational and personal financial planning purposes only. It does not provide investment, tax, or legal advice or recommend specific financial products. Consult a CPA, tax professional, or financial advisor for guidance on your situation.

Calculations assume constant returns and exclude taxes, fees, inflation, and market volatility. Tax rules (401(k), IRA, HSA, 529 limits, RMDs, SECURE Act 2.0) change annually; verify with the IRS or your plan administrator.

Terms of Use:
https://cicalc-74e14.web.app/en/info#terms