FinMathFinMath

HP 19BII+ Financial Calculator

Algebraic by default, with optional RPN — a menu-driven financial calculator in your browser. Time-value-of-money, cash-flow NPV/IRR, and bond price/yield, via guided forms or a classic keypad.

Two ways to use it. The forms below (FIN → TVM / CFLO / BOND) let you type inputs directly — no keystroke memorization needed. Advanced users can switch to ALG or RPN on the keypad for expression entry. This MVP covers the FIN menu; date math, statistics, and the equation Solver are coming soon.
finMATH 19BII+
BUSINESS CONSULTANT
0.00
ALG FIN·TVM END FIX 2

FIN · TVM Time-Value of Money

Sign convention: inflows positive, outflows negative.

Why the HP 19BII+ is friendlier than the 12C

The original HP 19BII and its modern successor the 19BII+ were Hewlett-Packard's answer to finance professionals who wanted the power of the 12C without having to learn Reverse Polish Notation. The 19B offers a two-line LCD showing the expression you're typing and its running value, softkeys that relabel themselves depending on the menu (FIN, BUS, SUM, TIME, SOLVE), and a menu-driven time-value-of-money solver that looks a lot like filling in a form. For anyone trained on a grade-school algebraic calculator — (3 + 4) × 5 = — it feels immediately natural.

What this MVP covers

This first release implements the HP 19BII+'s most-used menu, FIN, in three parts:

  • TVM — a full time-value-of-money solver for N, I/YR, PV, PMT, FV with configurable payments per year and BEGIN/END mode. It uses the same closed-form expressions and Newton iteration as the hardware.
  • CFLO — a grouped cash-flow register for NPV and IRR. Enter an initial outflow in period 0, then one row per distinct cash-flow amount with a repeat count.
  • BOND — fixed-coupon bond pricing with annual, semi-annual, or quarterly coupons. Solve clean price from YTM, or YTM from price, using Newton–Raphson on the yield.

The keypad on top accepts both algebraic expressions (default) and RPN. In ALG mode, you type as you would on a grade-school calculator: 300000 × 0.065 ÷ 12 and then = to see the result. The upper LCD line shows the expression history; the lower shows the current value. In RPN mode, the keypad flips to a 4-level stack (press = for ENTER). Form inputs and keypad inputs share the same TVM / cash-flow / bond registers, so you can mix and match.

A quick worked example: mortgage payment

Take a 30-year mortgage for $300,000 at 6.50% annual interest. In the TVM form:

  • N = 360 (30 years × 12 months)
  • I/YR = 6.5
  • PV = 300000 (positive — a cash inflow from the lender's perspective)
  • FV = 0
  • P/YR = 12, Mode = END
  • Calculate = PMT → click Calculate

Result: −1,896.20. The minus sign means the payment is your monthly outflow. Switch Calculate to N and raise PMT to −2,500 to see how much faster the loan would be paid off.

NPV and IRR on a project

Suppose you invest $100,000 today, receive $30,000/year for the next four years, and then a final $40,000 in year five. In CFLO, enter −100000 in period 0, 30000 with count 4, and 40000 with count 1. Set I% to 8 and click Compute NPV to get the net present value; click Compute IRR for the internal rate of return.

HP 19BII+ vs HP 12C — which should you use?

If you grew up on algebraic calculators and you want clear menu-driven guidance, pick the 19BII+. If you're a CFA/FRM candidate, a veteran appraiser, or you already have RPN muscle memory, the HP 12C will feel faster because every financial operation is one keystroke away without menu navigation. Both tools share the same underlying math; the interface is what's different.

Roadmap

This MVP ships with FIN only. Next up: the SOLVE menu (enter a custom equation and auto-solve any variable), TIME (date differences and loan schedules), BUS% (markup, markdown, percentage change), and 1-variable / 2-variable statistics with forecasting — matching the layout of the hardware. Suggestions? Send feedback.