Compound Wealth Simulator vs InterestLab

Compound Interest Calculator helps you visualize long-term investments with realistic, inflation-adjusted projections. Reverse-calculate from your savings goal, set independent contribution and growth periods, and plan with confidence for FIRE, retirement, or any long-term financial milestone. ■ Who this is for - Anyone planning long-term investments (IRA, Roth IRA, 401(k), ISA, NISA, iDeCo) - The FIRE community - Retirement planners - Goal-based savers - Inflation-conscious investors ■ 3 Calculation Modes - Calculate — Future value from initial assets and contributions - Reverse — Required monthly contribution to reach your goal - Compare — 3 return scenarios side by side ■ Independent Contribution Period Set your contribution years separately from your overall growth period (e.g. contribute for the first 10 years of a 30-year horizon, then let the balance compound). The chart highlights when contributions stop with a visual marker. ■ "Time to Goal" Reverse Calculation Calculate how long it takes to reach your target as "X years Y months." Just enter your monthly contribution and assumed return rate. ■ Inflation-Aware Display both nominal and real (purchasing-power) returns. Especially useful for users in high-inflation economies who want to understand the true future value of their savings. ■ 23 Currencies, 7 Languages Major world currencies including USD, EUR, GBP, JPY, CNY, KRW, INR, BRL, MXN, TRY. UI in English, Japanese, Chinese, Korean, Hindi, Spanish, and Portuguese. ■ Locale-Aware Number Formatting - Japan / China — 万, 億, 兆 - India — Lakh, Crore - English-speaking — K, M, B, T Numbers display in the format locals naturally read. ■ Privacy & Ads - All calculations happen on-device. Your input data is never sent to our servers. - This app is free, supported by in-app advertising. ■ Technical - iOS 15.6 or later - iPhone only ■ Disclaimer Calculations are simulations and do not guarantee future investment performance or inflation rates. Investment decisions are your own responsibility.

InterestLab is a complete financial calculator toolkit for everyday money decisions — from mortgages and loan payoffs to savings, interest rates, and dates. Clean, fast, and fully offline. Whether you're comparing a home loan, planning to pay off a credit card faster, or projecting how your savings will grow, InterestLab gives you clear numbers, helpful charts, and a shareable PDF — all in seconds. WHAT YOU CAN DO . Mortgage — Enter the home price, down payment, rate, and term to see your monthly principal & interest, total interest, payoff date, a balance-over-time chart, and a full amortization schedule you can export as a PDF. . Loan Payoff — See how long until a balance is paid off and how much interest you'll pay. Add an extra monthly amount to see the time and interest you'd save. . APR ↔ APY — Convert between the nominal (APR) and effective (APY) annual rate for any compounding frequency — the fast way to compare loan and savings offers. . Savings with Deposits — Project growth with recurring monthly deposits, an optional yearly deposit increase, and inflation. Watch it build with a growth curve and an invested-vs-earnings breakdown. . Fixed Income — Model a lump-sum investment over days, months, or years, with inflation-adjusted results. . Loan Rate Finder — Discover the true interest rate hidden in a set of fixed payments — perfect for comparing financing offers. . Variable Income — Track gains and losses on any asset from purchase to sale, with daily, monthly, and annual rates. . Gains (Run-up) & Losses (Drawdown) — Understand the percentage needed to recover a loss, or given back after a gain. . Equivalent Rates & Stated Rate — Convert rates between periods and work with stated/effective rates (SAR / ER). . Dates — Days between two dates (calendar and business days), add or subtract time, and track ages, events, and anniversaries. . History — Save any calculation, search your records, and export or share results as a clean PDF. BUILT FOR PRIVACY InterestLab works fully offline. There are no accounts, no sign-in, no ads, and no tracking. Everything you calculate and save stays on your device — we never see your data. SIMPLE, POLISHED, FAST A tidy home screen, native charts, haptic feedback, Dark Mode, and Dynamic Type support make InterestLab a pleasure to use on any iPhone. PREMIUM (OPTIONAL) The free version covers everyday calculations. A single one-time purchase unlocks unlimited terms for long-range projections — no subscription, ever. Disclaimer: InterestLab provides estimates for informational purposes only and is not financial, tax, or legal advice. Always verify results and consult a professional before making financial decisions.