About
A BA II Plus you can practise on anywhere
This site exists because the calculator you need is always on the other desk. It is a free, browser-based emulator of the TI BA II Plus — all nine worksheets, all 44 keys — with 10 dedicated calculators beside it that show the formula behind every number they give you.
What this is
Two things, built to be used together. The emulator is the device
itself: the 2ND key arms and disarms, CPT waits for the variable you want, and
every worksheet steps with ↑ and ↓ the way the hardware does. Drive
it with the mouse or type straight into it — digits, operators, Enter,
Backspace and the arrow keys all map through.
The dedicated pages solve the same problems as web forms, for the times you want the working rather than the keystrokes. Each one prints the formula it used with your own figures substituted in, next to the schedule or chart behind the result, so you can hand in the method and not only the answer.
How the arithmetic is checked
Time value of money, IRR, bond price and yield, the depreciation methods and the regression models are each covered by an automated test suite that runs before anything ships. The emulator's tests drive the state machine one key at a time — exactly as a visitor would — and assert on what lands on the LCD, so the keystroke behaviour and the display formatting are checked together against published worked examples.
That is a claim about method, not a guarantee of every figure. If you find a number you cannot reproduce on the hardware, tell us the keystrokes and it gets looked at.
Where it differs from the hardware, on purpose
Two behaviours are deliberately not faithful, because being faithful was the worse option:
- Six decimal places, not two
- The hardware ships showing two. Rates, factors and durations are usually decided in the third to sixth place, so the emulator shows six and rounds only for display — the internal value keeps full precision.
- One press of CE|C resets everything
- On the device, CE|C clears the entry first and the display second. Here a single press returns a fresh calculator: every register, every worksheet, gone. It is the thing you actually want between two problems, and there is no risk of carrying a stale P/Y into the next one.
Everything else — chain arithmetic and its order of operations, parenthesis depth, the sign convention, the worksheet field order — follows the exam-room device.
What this site does not do
There is no account, no sign-up and no paywall, and nothing is held back behind one. The maths runs entirely in your browser: the figures you type are never sent anywhere, because there is nowhere for them to go. No analytics script, no advertising script and no cookie wall — the site stores two preferences (your light or dark setting and your chosen calculator skin) in your browser's own storage and nothing else. The privacy policy spells out the one third-party request the pages do make.
What it is not
It is an independent educational tool. BA II Plus™ is a trademark of Texas Instruments Incorporated, and this site is not affiliated with, endorsed by or sponsored by Texas Instruments. Nothing here is financial, investment or tax advice — see the disclaimer — and no online calculator is permitted in the CFA, CFP or FRM exam room, so drill the keystrokes here and rehearse them on the device you will actually carry in.
Get in touch
Found a number that looks wrong?
Corrections are the most useful mail this site gets. Send the keystrokes and the answer you expected, and the fix ships with a test that keeps it fixed.