BA II Plus vs HP 12C for CFA candidates

The Chartered Financial Analyst (CFA) Institute permits exactly two calculators in the exam room: the Texas Instruments BA II Plus (standard and Professional) and the Hewlett-Packard HP 12C (standard, Platinum, and Anniversary editions). Both clear the bar. Both compute the same answer to the same precision on any CFA question. The choice between them is a choice of learning curve, interaction style, and personal taste, not a choice of capability.

Charterly is a free CFA calculator companion that runs on both devices. The same engine answers both, so a candidate who uses Charterly during prep can switch any time without losing practice history or saved scenarios. That is the position this page is written from. The recommendation at the end is candid because Charterly does not benefit from either choice.

Try the BA II Plus calculator

Try the HP 12C calculator

Contents

1. The short answer
2. Side-by-side comparison
3. Interaction style: algebraic vs RPN
4. Cost and availability
5. Learning curve and keystroke count
6. Reliability and exam-day robustness
7. If you already own one
8. Recommendation
9. Frequently asked questions

1. The short answer

If you have never used either calculator and you are starting CFA prep, buy the BA II Plus. It has a shorter learning curve and the prep-provider ecosystem leans BA II Plus, so most third-party content you will reference assumes that device.

If you already own an HP 12C, or you already think in Reverse Polish Notation (RPN), or you work in fixed income where RPN is common, keep the HP 12C. The learning curve cost of switching to the BA II Plus is not worth the marginal time savings on the exam.

Both calculators answer every CFA question to the same precision. The exam time difference between the two is measured in seconds across a six-hour day, not in minutes.

2. Side-by-side comparison

The device history points above are stable across decades. Retail pricing moves by country, retailer, and inventory cycle, so check current listings before you buy. Both devices have a long, predictable reliability record.

3. Interaction style: algebraic vs RPN

The biggest split between the two devices is how you enter expressions.

BA II Plus uses algebraic input (with two operating modes, Chain and Algebraic Order, that affect operator precedence). To compute 2 + 3 × 4 you type 2 + 3 × 4 =. In Algebraic Order mode, you get 14. In Chain mode, you get 20. Pick Algebraic Order (AOS) for CFA work.

HP 12C uses Reverse Polish Notation (RPN). To compute 2 + 3 × 4, you push values onto a four-register stack and then apply operators: 2 ENTER 3 ENTER 4 × +. The result is 14. There is no precedence to remember because the stack does the work.

For a candidate who already thinks in RPN, the HP 12C is dramatically more efficient for chained calculations. The four-register stack holds intermediate values, no parentheses needed, no equals key to forget.

For a candidate who has never used RPN, the HP 12C is a calculator with a foreign language. The first week of practice feels slow and error-prone. By the second week, most candidates either click with RPN or quietly give up.

Worked example. A candidate computes (1.05 ^ 10 - 1) / 0.05 to value a 10-year annuity factor.

On the BA II Plus (AOS mode): 1.05 y^x 10 - 1 = ÷ 0.05 =. Result: 12.5779.

On the HP 12C: 1.05 ENTER 10 y^x 1 - 0.05 ÷. Result: 12.5779.

The HP path is one keystroke shorter. Over the six-hour exam, that difference accumulates into maybe 30 seconds. The decision is not driven by speed.

4. Cost and availability

Both calculators are widely available from major retailers in North America, the UK, the European Union, and Asia. Both have refurbished and used markets. The HP 12C often sells at a meaningfully higher retail price than the BA II Plus.

If cost is a deciding factor, BA II Plus is the answer.

If cost is not a deciding factor, the price difference is a small share of total prep spend (curriculum, mock exams, registration). It should not be the deciding factor for most candidates.

5. Learning curve and keystroke count

A candidate who learned arithmetic the standard way will be productive on the BA II Plus within a session. Productivity on the HP 12C typically takes a week of deliberate practice for someone new to RPN.

Once productive on either device, the keystroke counts for the four most common CFA workflows are close:

The HP is consistently one or two keystrokes shorter per problem because RPN folds the equals key into the operator. Over the 90 calculator-using items on a typical six-hour exam day, the cumulative difference is small.

The bigger source of time savings on the exam is not which device you chose. It is whether you cleared TVM between problems, set Periods per Year correctly, and avoided the BGN-mode trap. Charterly's calculator companion catches those state mistakes on both devices. The twelve CFA calculator mistakes page lists the rules.

6. Reliability and exam-day robustness

Both calculators are mechanical and have a long failure-mode track record:

• BA II Plus. Battery compartment can fail if the calculator has been stored unused for years. Replace the battery the week before the exam.
• HP 12C. Two LR43 batteries. The HP 12C has a famously long battery life (often years), but the rule of thumb is the same: replace before the exam.

Bring a spare calculator on exam day. The CFA Institute calculator policy allows two of the approved models in the exam room. Some candidates carry one of each as a hedge if they own both.

7. If you already own one

Keep it. Re-training muscle memory on a different device a few months out from the exam is a losing trade. The first week of switching is slow and error-prone, and that fragility persists for longer than most candidates expect.

The only exception is if you own an HP 12C, have struggled for a month, and still feel slow on RPN. RPN does not click for every candidate. Switching to the BA II Plus is a defensible call if you give yourself at least eight weeks to retrain before the exam.

Charterly preserves practice history, saved scenarios, and dashboard analytics when you change the device preference. Switching is one toggle in Settings.

8. Recommendation

For most candidates starting CFA prep with no prior calculator preference: buy the BA II Plus. Lower learning curve, prep-provider ecosystem leans that way, cheaper, plenty.

For candidates who already think in RPN, work in a field where RPN is common (fixed-income trading, some engineering disciplines), or already own an HP 12C: use the HP 12C. The exam time savings are real if marginal, and the device's long life means it will outlast the exam.

For candidates who are still undecided: open both in Charterly and run the same TVM problem on each. Pick the one that feels less effortful after ten minutes. The choice is small.

9. Frequently asked questions

Does the CFA Institute allow any other calculators? No. The CFA Institute's exam policy permits only the Texas Instruments BA II Plus (standard and Professional) and the Hewlett-Packard HP 12C (standard, Platinum, and Anniversary editions). Confirm on the CFA Institute's calculator policy page before exam day, because policies can change.

Will I be slower on the exam if I pick the HP 12C as a new RPN learner? Initially yes, after eight weeks of practice no. The exam-day speed difference between the two calculators, for a fluent user, is small.

Can I bring two calculators into the exam room? Yes. The policy explicitly allows two approved models. Carry a spare with fresh batteries.

Should I buy the BA II Plus Professional or the HP 12C Platinum? Standard versions are enough for most Level I curriculums. The Professional and Platinum variants add a few keys that are useful for Level II (modified duration, breakeven analysis on the TI side; algebraic mode on the HP side) but neither is required.

Does Charterly cost more if I want both calculators? No. Charterly's free tier includes both calculators, the twelve mistake rules across both devices, and the LOS tagged practice library. Charterly Pro lifts the daily drill cap and adds mock exams and advanced calculators, and it covers both devices too.

Where can I read the device-specific setup walkthroughs? The BA II Plus CFA guide and the HP 12C CFA guide cover the four-step setup and four worked examples on each side.