250+ iOS apps curated and reviewed
The best simple interest calculator apps on iPhone average 4.5★ across 250+ titles — we've ranked them by what real users actually keep on their phones. Updated September 2026.
| # | App | Price | Rating | Ads | In-App Purchases | Updated | |
|---|---|---|---|---|---|---|---|
| 1 |  | Free | 3.7★ (3) | No | No | Aug 2026 | |
| 2 |  | Free | 4.9★ (105K) | Yes | No | Sep 2026 | |
| 3 |  | Free | 4.6★ (23K) | Yes | Yes | Sep 2026 | |
| 4 |  | Free | — | No | No | Sep 2026 | |
| 5 |  | Free | — | Yes | Yes | May 2026 | |
| 6 |  | Free | 5.0★ (2) | No | No | Jul 2026 | |
| 7 |  | Free | — | Yes | No | Aug 2026 | |
| 8 |  | Free | — | Yes | No | Sep 2026 |
This tool quickly and accurately calculates simple interest based on amount, interest rate, and duration. It supports calculations for monthly or yearly rates and can determine interest between specific dates or for a given period in years, months, or days.
Easily calculate loan or mortgage payments. Simply input the loan amount, repayment term, and interest rate to get your estimated monthly payment.
This app helps you understand the true cost of loans and mortgages by revealing total interest paid and payoff timelines. It allows for scenario comparisons, extra payment analysis, and detailed amortization schedules. Visualize your debt journey with graphs and access bonus calculators.
