HP 20b

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HP 20b
Hp20b business calculator.jpg
HP 20b
Latest firmware2010-04-05
SuccessorHP 30b
CostUSD 15 - 40
Entry modeRPN, Algebraic, Chain
Display typeLCD seven-segment display dot-matrix display
Display size12+3 digits and 8 characters
Processor30 MHz Atmel AT91SAM7L128 (ARM7TDMI core)
Memory register50 pairs of statistical data + 10 registers
Power supplyCR 2032 batteries (1 required, 1 optional)
Power consumption0.25 mW
Weight113.2 g
Dimensions14.92 × 7.70 × 1.6 cm

The HP 20b Business Consultant (F2219A, codenamed "Little Euro"[6]) is a financial calculator published in 2008 by Hewlett-Packard. Its function is similar to HP 10bII and includes scientific and statistical functions.

Hardware specification[edit]

The HP 20b uses a 2 lines display with the first line an 8 character scrolling display and 11 indicators and the second line for 12+3 digit display. It also uses 2 CR2032 batteries, an Atmel AT91SAM7L128 30 MHz processor. The processor's serial interface is accessible from under the battery cover to allow the firmware to be updated using a special cable from HP.


The HP 20b contains functions similar to the HP 10bII, with financial functions including: TVM, IRR, NPV, NUS ("Net Uniform Series"[7]), amortization, depreciation, bonds, yield and accrued interest, interest conversion, list-based cashflow analysis, cashflows, break-even analysis.

Math/Statistics functions include: list-base, 1 and 2 variable statistics, mean, standard deviation, population deviation, standard error, forecasting, correlations and covariance, +, -, ×, ÷, %, 1/x, +/-, scientific notation, n!, combinations, permutations, rounding, random numbers, LOG, LN, 10×, PL, square root, trigonometry, probability.[8]

For input modes, it supports RPN, Chain and Algebraic input.

It also included several added features include: date calculation, display format and language preferences, memory functions, editing, scroll keys.


Many users claim that they dislike the model because it lacks the feedback when pressing the keys, and the menus make things complicated.[9]

Examination approval[edit]

The HP 20b is approved by the Hong Kong Examinations and Assessment Authority and can be used in Hong Kong Certificate of Education Examination of 2009 or later.[10]

The HP 20b is approved by the Global Association of Risk Professionals (GARP) and can be used for the Financial Risk Manager (FRM) certification exam.[11]

HP 20b with overlay for WP 34s

Repurposing as the WP 34S[edit]

Along with the HP 30b, the HP 20b calculator is particularly conducive to repurposing, since both the hardware and software are made public by HP. Several projects have been started around reusing this calculator for other purposes. The most advanced is the WP 34S, a programmable scientific calculator that combines the functionality of the HP-42S and HP-16C and includes many other novel features and functions.[12][13] The WP 31S is a stripped-down non-programmable version of the WP 34S, designed to be easier to use.

See also[edit]


  1. ^ http://h20331.www2.hp.com/hpsub/downloads/HP_Calculator_eNL_04_Apr_2013_v1.pdf
  2. ^ http://media.digikey.com/pdf/PCNs/Atmel/RE133101_AT91SAM7Lxx_Obs.pdf
  3. ^ http://media.digikey.com/pdf/PCNs/Atmel/RE133101_AT91SAM7Lxxx_Retract.pdf
  4. ^ http://media.digikey.com/pdf/PCNs/Atmel/SE133406A_Obs.pdf
  5. ^ http://media.digikey.com/pdf/PCNs/Atmel/RE150402.pdf
  6. ^ http://www.hpmuseum.org/forum/thread-10744.html
  7. ^ [1]
  8. ^ HP 20b Functions
  9. ^ Criticisms of the HP 20b
  10. ^ http://www.hkeaa.edu.hk/DocLibrary/IPE/cal/CAL2014.pdf
  11. ^ http://www.garp.org/frm/exam-overview/testing-policies-and-procedures/calculator-policies.aspx
  12. ^ WP 34S repurposing project
  13. ^ Gene Wright (2011-06-29). "The 20b / 30b has been repurposed into a scientific calculator - The 34S !". HP Communities. Retrieved 2011-08-17.

External links[edit]