CompoundFX is developed by Origin Software, Inc. It's a compound interest calculator for iPhone, built in native SwiftUI for iOS 17 or later. It runs fully offline with no third-party SDKs, no accounts, and no data collection. Free to download. Optional one-time Pro upgrade. No subscription.
What CompoundFX does
CompoundFX projects how an investment grows from a starting principal, a rate of return, and a deposit schedule, with a real-time growth chart, a year-by-year breakdown, and inflation, tax, and expense-ratio adjustments. The optional Pro purchase adds Goal Mode, which works backward from a target amount, along with unlimited saved scenarios, side-by-side scenario comparisons, and two-page PDF reports. See every feature, Free and Pro, or get CompoundFX on the App Store. Origin Software also has a CompoundFX product page.
This website
This site is the home of CompoundFX. Alongside the product pages, it offers a free web calculator, calculators for savings, retirement, FIRE, and inflation, and an educational guide to compound interest, all built on the same privacy-first principles as the app.
How our numbers are computed
Every figure on this site (every table, worked example, and chart) is computed at build time by a single, fully unit-tested TypeScript calculation engine; nothing is estimated, hand-copied, or borrowed from another source. Displayed values follow a strict rounding convention: derived figures are calculated from the rounded numbers you actually see, so every comparison on the site reconciles by hand. The interactive calculators run that same engine in your browser, which is why the static examples and the live results always agree.
About Origin Software
Origin Software, Inc. builds focused, privacy-first tools that do one thing well: no accounts, no ads, no data collection. We're a small independent studio, founded in 2005 and now in our third decade, building production software across financial services, life sciences, and consumer apps. You can find the rest of our work at originsoftware.net.
Who's behind it
Origin Software was founded by George Catobus, who brings more than twenty years of enterprise architecture experience across life sciences and financial services. He previously founded CommissionSpot, which was acquired by Ellie Mae. Origin Software is the continuation of a simple conviction from that work: the best software is focused, fast, and respectful of the people using it, which is why everything we ship is privacy-first by design.
Get in touch
For help with the app, start with CompoundFX Support. Questions, corrections, or feature ideas are always welcome. Just contact us.