Par: Loan Financial Calculator
Mortgage, car, TVM, bonds, APR
$9.99
Every solve lands on a tape you can label, print and hand over. Ten tools, one document, no subscription and no account. Buy it once; it works offline, forever.
Par is a financial calculator that keeps its work.
Every number you solve lands on a tape — labelled, editable, saved as a document you can reopen
tomorrow, print, or export as text or CSV. Change one input on line two and only line two changes.
The tape is the point: it is what turns a calculation into something you can hand to a client, a
loan committee, or your future self.
TEN TOOLS, ONE DOCUMENT
• Time value of money — solve for any of n, i, PV, PMT or FV from the other four, with payments at
the beginning or the end of the period
• Amortization — a real, scrollable schedule with interest, principal and balance per period, by
year or every period, printable and exportable
• Cash flow — NPV and IRR over grouped flows, and an honest answer when no rate balances them
• Bond — price, yield to maturity, accrued interest, invoice price, current yield, Macaulay and
modified duration, convexity
• Rate and APR — nominal to effective, APR from a loan's actual cash flows
• Depreciation — straight line, declining balance, sum of years' digits and MACRS tables
• Dates and day count — 30/360, 30E/360, 30E/360 ISDA, Actual/Actual ICMA, Actual/360, Actual/365,
side by side, because they disagree and the difference is money
• Percent and margin — change, markup, margin, break-even
• Statistics — one and two variable, with linear fit
• Real estate — NOI, cap rate, and loan sizing that tells you whether DSCR or LTV is the binding
constraint
NUMBERS YOU CAN CHECK
Most calculators ask you to trust them. Par's maths is written against published authorities and
locked down by an automated test suite that compares its output to worked examples from the source
documents themselves:
• U.S. Treasury pricing and accrued interest — 31 CFR Part 356, Appendix B
• APR — Regulation Z, 12 CFR 1026, Appendix J
• APY — Regulation DD, 12 CFR 1030, Appendix A
• MACRS — IRS Publication 946, Appendix A tables
• Day count conventions — 2006 ISDA Definitions, Section 4.16
• Statistical routines — NIST/ITL reference datasets
Every screen shows which authority and which convention produced the number on it. Where a
published table and the continuous formula genuinely disagree, Par says so rather than quietly
picking one.
BUILT FOR THE WAY YOU ACTUALLY WORK
• Universal — one purchase covers iPhone, iPad and Mac
• Fully offline. No network code, no analytics, no account, nothing to sign in to
• Split View and Stage Manager on iPad, where the tape sits beside the calculator
• Dynamic Type throughout, VoiceOver labels on every control
• Dark, high-contrast interface designed for long sessions
HONEST PRICING
One purchase. No subscription, no advertising, no in-app purchases, no "pro" tier holding half the
tools hostage. What you see here is the whole app.
Par is for anyone who has to show their work: mortgage and commercial real estate people, treasury
and banking analysts, accountants, CFA and finance students, and anyone who has ever re-typed the
same twelve numbers because the last answer scrolled away.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Koreniuk Oleksandr, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Koreniuk Oleksandr
- Size
- 1.7 MB
- Category
- Finance
- Compatibility
Requires iOS 26.0 or later.
- iPhone
Requires iOS 26.0 or later. - iPad
Requires iPadOS 26.0 or later. - Mac
Requires macOS 26.0 or later. - Apple Vision
Requires visionOS 26.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Olexander Koreniuk
