CompoundFX: Compound Interest

CompoundFX is the compound interest calculator that shows you what it takes, not just what you'll have. Model investment growth, plan for retirement, and pressure-test your FIRE goals with precision.

Set a goal, $1M by age 60, a down payment, or a college fund, and CompoundFX solves for the missing piece. The rate you’ll need. The years it will take. The deposit you have to make. No more guessing. No more trial and error.

GOAL MODE
Pick your goal. Choose what to solve for. CompoundFX does the financial math.
- Solve for Rate of Return
- Solve for Time Horizon
- Solve for Starting Principal
- Solve for Monthly Contribution

COMPARE SCENARIOS
Should you save more or invest longer? Pay off debt or boost your 401(k)? Save scenarios and put them head-to-head. See the difference, the total dollar impact, and exactly when one strategy pulls ahead.

A CALCULATOR THAT SHOWS ITS WORK
- Real-time growth chart with milestone markers ($100K, $250K, $1M)
- Year-by-year breakdown with full transparency
- Inflation, Taxes, and Expense Ratios: See what you actually keep after fee drag
- Daily, weekly, monthly, or annual contributions
- Custom compounding intervals (Daily to Annually)
- Sub-year precision for short-horizon plans

DESIGNED FOR iPHONE & INDIE DEV
Dark glass UI. Smooth haptics. Built natively in SwiftUI for iOS 17 and up. No accounts. No ads. No tracking. Your scenarios stay locally on your device.

EXPORT AND SHARE
Generate a polished two-page PDF report with an executive summary, growth chart, and full milestone breakdown. Or share a branded image to text or social media.

FREE FEATURES
- Full compound interest calculator
- Real-time growth chart and year-by-year table
- Inflation, tax, and expense adjustments
- Custom contribution and compounding schedules
- Branded image sharing

PRO: $4.99 (ONE-TIME PURCHASE)
- Goal Mode (Solve for any missing variable)
- Save unlimited scenarios
- Compare scenarios side-by-side
- Export two-page PDF reports

One purchase. Unlocked forever. Family Sharing fully supported.

WHO IT'S FOR
Whether you're starting your first Roth IRA, managing index funds, planning early retirement, modeling a college fund, or tracking a Bogleheads portfolio, CompoundFX gives you the answer in seconds.

PRIVACY FIRST
CompoundFX is fully offline. No data collection. No accounts required. No analytics. No third-party SDKs. Your personal finance data is stored safely on your device.

DISCLAIMER
CompoundFX is for educational and planning purposes. It does not provide investment, tax, or financial advice. Returns shown are projections based on the inputs you provide and do not guarantee actual investment performance.

Questions or feedback? support@originsoftware.net