# Kaeseru Loan Payoff Calculator — Mortgage Extra Payment & APR

> Loan payoff calculator for rate changes, prepayments, and effective APR. (iPhone/iPad app by Daisuke Yamaguchi.)

- Source: https://appshunter.io/ios/app/kaeseru-loan-payoff-calculator/id6796657244 (this page in markdown: same URL + `.md`)
- Developer: [Daisuke Yamaguchi](https://appshunter.io/developer/880950899)
- Category: Finance, Utilities
- Price: $0.99
- Age rating: 4+
- Requires: iOS 17.0 · 4 MB
- Languages: American English, German (Germany), Japanese
- Released: 2026-08-05
- Data updated: 2026-10-31
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/kaeseru-loan-payoff-calculator/id6796657244/reviews.md

## What is Kaeseru Loan Payoff Calculator?

“If the rate goes up 1%, how much more do I pay each month?”
“If I make a $10,000 overpayment, how much interest do I really save?”

Kaeseru answers those questions in money – the exact difference between doing it and not doing it – instead of a vague chart.


■ Extra payments, answered in money
Choose when and how much, and Kaeseru shows first how much interest you save and how many months sooner you are mortgage-free.
It runs both options at once – keep the payment and shorten the term, or keep the term and lower the payment – so you can see which is better. Prepayment fees are subtracted too.

■ Compare up to 5 saved plans side by side (new)
Fixed vs. variable, 25 vs. 30 years, a bigger deposit. Save the scenarios and compare 2–5 of them in one table: monthly payment, rate, APR, term, total cost including fees, total interest, interest share and payoff date. Every plan is shown as a difference from your baseline, and the cheapest plan is marked. Export the table as CSV or share it as text.

■ See a rate rise before it happens
+0.5%, +1.0%, +2.0% and your own worst case, side by side, with the extra monthly cost of each.

■ The real rate including fees (APR)
Add arrangement, broker or valuation fees and Kaeseru calculates the APR, so you can compare offers on equal terms.

■ Solve for any of the four
Monthly payment, loan amount, term or rate – pick one and Kaeseru works it out from the other three.

■ Built for the United States
・US dollars, 30- and 15-year terms and APR out of the box
・Amounts in your currency to the cent, with a choice of rounding (down, half up, up) to match your lender's schedule
・Level payment (annuity) and level principal
・Terms up to 50 years (600 payments)
・Full amortization schedule, monthly or yearly, with CSV export
・Every formula shown on screen, so you can check the numbers

■ What this app never does
・No ads (no ad SDK)
・No in-app purchases or subscriptions – a single one-time purchase unlocks everything
・What you enter never leaves your device. To improve the app, only anonymous usage data (such as which screens are opened) is counted with Google Analytics (you can turn this off in Settings).

Results are estimates. Actual payments depend on your lender's calculation method; always check your lender's official schedule.

Kaeseru is made by Sauna Inc., Tokyo.

## Key features

- Calculate interest savings from prepayments
- Simulate loan rate increase scenarios
- Determine effective annual rate (APR)
- Solve for payment, borrowing capacity, term, or rate
- Export amortization schedules as CSV
- Compare saved loan plans side-by-side

## Is Kaeseru Loan Payoff Calculator safe?

Not enough ratings yet to assess Kaeseru Loan Payoff Calculator.

## Is Kaeseru Loan Payoff Calculator legit?

Kaeseru Loan Payoff Calculator appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for Kaeseru Loan Payoff Calculator is 75 out of 100 points across 7 verification signals from App Store and developer data.

## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/kaeseru-loan-payoff-calculator/id6796657244/reviews.md

### 5/5 — 「住宅ローンを組む前に入れておきたいアプリ」

*2026-08-07*

住宅ローンの返済額や繰り上げ返済の効果が一目で分かるので、とても参考になりました。難しい知識がなくてもシミュレーションできるので、家を買う予定がある人やローンを見直したい人には入れておいて損はないアプリです。

## Frequently asked questions about Kaeseru Loan Payoff Calculator

### Does Kaeseru have ads?

No, Kaeseru is ad-free. The app explicitly states that no ad SDK is bundled and it contains no advertisements.

### How much does Kaeseru cost?

Kaeseru is a paid app priced at $0.99. This one-time purchase unlocks all features without any in-app purchases.

### What devices does Kaeseru support?

Kaeseru is available for iPhone and iPad devices. It is designed to run on Apple's mobile operating system.

### How often is Kaeseru updated?

Kaeseru was last updated on August 9, 2026, with version 1.2. This indicates a recent update and ongoing support.

### Is Kaeseru safe for all ages?

Kaeseru has an age rating of 4+, making it suitable for a wide audience. It does not collect user data or require network requests.

### Can Kaeseru calculate Japanese variable-rate loan specifics?

Yes, Kaeseru can simulate scenarios with the 5-year rule and 125% cap common to Japanese variable-rate loans, showing deferred interest and balance shifts.

### How does Kaeseru handle loan fees?

Kaeseru includes origination fees, guarantee fees, and monthly insurance in its calculations to provide the real effective annual rate (APR), not just the headline rate.

### Can I reconcile Kaeseru's calculations with my lender?

Yes, Kaeseru allows you to choose how fractional yen are rounded (down, nearest, or up) to help you reconcile the app's calculations with your lender's official schedule.

## Version history (last 5 releases)

### 1.7 — 2026-10-23

Minor improvements.

### 1.6 — 2026-10-12

Minor improvements.

### 1.5 — 2026-09-30

• The app now counts anonymous usage (such as which screens are opened) to help us improve it. Amounts and plan names are never sent. You can turn this off in Settings.
• Fixed the quick-step buttons for the loan amount wrapping onto two lines on narrow iPhones.

### 1.4.1 — 2026-09-28

Fixed the interest rate field running off the edge of the screen, and fixed the number keyboard not closing after you enter a value.

### 1.4 — 2026-09-27

Compare up to 5 saved plans side by side.

• In the Plans tab, pick 2–5 plans and tap “Compare side by side” to see monthly payment, rate, APR, term, total cost (incl. fees), total interest, interest share and payoff date in one table
• Every plan is shown as a difference from the first one you picked, and the cheapest plan is marked
• Export the comparison as CSV or share it as text

Also new
• The app is now available in English and German, with US, UK, Australian and Canadian dollars / pounds / euros. Change it any time under Settings → Country & currency
• Semi-annual compounding for Canadian fixed-rate mortgages

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All apps by Daisuke Yamaguchi: https://appshunter.io/developer/880950899

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-31.*