Feature  CALC 1  HP 12C Based  HP 10bii Based  HP 17Bii+ Based  TI BA Plus Based 

Chain Calculation Mode (no operator precedence. 2+3×4 = 20.00) 
✔ 
✔ 
✔ 
✔ 

Algebraic Calculation Mode (operator precedence. 2+3*4 = 14.00) 
✔ 
✔ 
✔ 

2+(3×4 = 14.00 (right parenthesis is not always required?) 
✔ 
No parenthesis on this app?! The hardware 12C with ALG has parenthesis.  error for missing right parenthesis.  ✔ 
✔ 
Display of 5÷2 before tapping = (is the left value and operator displayed?) 
5.00÷2 (CHN mode) 5/2 (ALG mode) 
2. (no left value or operator displayed) 
5/2 
5.00÷2  2. (no left value or operator displayed) 
RPN Calculation Mode  ✔ 
✔ 
✔ 

Single Digit Delete So you don't have to clear the entire number if you tap 1 wrong digit. 
✔ 
No. The hardware 12C with ALG has this feature. 
✔ 
✔ 
✔ 
# of lines in display  1 to 4, User selectable.  1  1  4  1 
Keys (Cols, Rows)  5 by 7  5 by 8  5 by 8  6 by 7 Top row has 5 keys 
5 by 9 
Undo to recover from mistakes  ✔ 

Recall calculation history results  ✔ 
✔ 

“K” key for repetitive calculations  ✔ 

✔ 

✔ 
Key Hints  ✔ 

Include Stack values in chain/algebraic calculations.  ✔ 
✔ 

Display of 1÷1000= when set to 2 decimal places (underflow).  0.001 
0.001  0.00  1.00E3  0.001 
# of User Memory (STO/RCL)  26 Not all 26 are available on all calculators. 
20  20  10  10 
Displays user memory values on key  ✔ 
Displays a list with values. 
Feature  CALC 1  HP 12C Based  HP 10bii Based  HP 17ii+ Based  TI BA Plus Based 

Standard TVM Calculator with N, I/YR, PV, PMT FV Keys (annual interest rates and P/YR)  ✔ 
✔ 
✔ 
✔ 

Standard TVM Calculator with N, i, PV, PMT FV Keys (odd period, periodic interest rate)  ✔ 
✔ 

Displays TVM values on or above respective keys.  ✔ 
✔ 

Form based TVM Calculator with label and input fields on one form.  ✔ 
✔ 

Separate P/YR and C/YR for Canadian mortgage and more.  ✔ 
✔ 

Bond Payment Frequencies/Date Basis  ann, semi, qrtly 30/360, A/A, A/360, A/365, e30/360 
semi 30/360 
No bonds  $$ for: ann, semi 30/360, AA 
ann, semi 30/360, AA 
ann, semi 30/360, AA 
Amortization Graphing  ✔ 
✔ 

Cash Flow Calculations  irr, npv, nfv, mirr  irr, npv  irr, npv $$ for nfv 
irr, npv, nfv, mirr,nus sppv, spfv, uspv, usfv 
irr, npv 
Depreciation  SL,SOYD,DB,DBX  SL,SOYD,DB  No Depreciation $$ for SL,SOYD,DB 
SL,SOYD,DB,Acrs  SL,SOYD,DB,DBX 
Graduated Annuities  ✔ 
Feature  CALC 1  HP 12C Based  HP 10bii Based  HP 17ii+ Based  TI BA Plus Based 

Percent Change, Percent of Total Keys 
✔ 
✔ 
%CHG  %CHG  
Percent Change, Percent of Total Calculators 
✔ 

✔ 

Markup Calculator  ✔ 
✔ 
✔ 

Breakeven Calculator  ✔ 
$$  ✔ 

Profit Margin Calculator  ✔ 
✔ 

Cost of Not Taking a Cash Discount Calculator  ✔ 

Economic Order Quantity Calculator  ✔ 

Newsvendor Model Calculator  ✔ 
Feature  CALC 1  HP 12C Based  HP 10bii Based  HP 17ii+ Based  TI BA Plus Based 

Standard stats, sum, average, standard deviation for xy  ✔ 
✔ 
✔ 
✔ 
✔ 
Entry of data from calculator (Σ+ or input Key) so calculation results can be used.  ✔ 
✔ 
Has Σ+ key but it opens an entry form.  ✔ 
✔ 
Enter and edit data from an editor form that shows all values.  ✔ 
This uses summary data so individual entries cannot be edited.  ✔ 
✔ 

Copy and paste data in editor  ✔ 

Automatically saves and restores list data  ✔ 
✔ 
Not automatic but lists can be saved and named.  
Stats: Median, Mode, variance, population SD,  ✔ 
✔ 

Curve Fitting Models  LIN, Ln, Exp, Pwr, Expnt, Inv  LIN  LIN $$ for Ln, Exp, Pwr, Expnt, Inv 
LIN  LIN, Ln, Exp, Pwr 
Factorial, Permutations, Combinations  ✔ 
n!  x! $$ for others 
✔ 
✔ 
Statistical Distribution  Normal, Student T, Log Normal, Binomial, Poisson  $$ for Normal, Student T  Solver functions for Normal, Student T. You need to build your own solver.  
Statistical Distribution Calculators  12  0  $$ for 2  0  0 
Feature  CALC 1  HP 12C Based  HP 10bii Based  HP 17ii+ Based  TI BA Plus Based 

ln, exp functions.  ✔ 
✔  ✔  ✔ 
✔ 
Trig and hyperbolic functions.  ✔ 
$$  ✔ 
✔ 

Additional functions  Over 190 functions Over 300 Unique keys on over 20 calculators Over 60 Formula Calculators 
Over 250 builtin Menudriven functions 
Feature  CALC 1  HP 12C Based  HP 10bii Based  HP 17ii+ Based  TI BA Plus Based 

Currency Conversions  31  0  0  Over 160  0 
UOM Conversions  ✔ 
✔ 

Automatically create calculator keys for 1tap currency or UOM conversion.  ✔ 
Create, save, load currency pairs 
Feature  CALC 1  HP 12C Based  HP 10bii Based  HP 17ii+ Based  TI BA Plus Based 

Record Keystrokes Programming  On the 12C calculator.  ✔ 

Create custom calculators  ✔ 

Create custom Formula Calculators or solvers  Uses spreadsheet compatible formulas and functions.  Uses HP specific functions. Has some functions (like Σ) that allow more complicated calculations.  
Graph Formula Calculators / solvers  ✔ 

The Formula Calculators / solvers display the variable values on key.  ✔ 

Automatic history logging of calculations and restoration of inputs.  ✔ 

Number of functions available to build Formula Calculators / solvers  Over 190 functions  71  
Available calculators that can be downloaded from app at no extra charge.  Over 20 Focused Calculators Over 60 Formula Calculators 
Feature  CALC 1  HP 12C Based  HP 10bii Based  HP 17ii+ Based  TI BA Plus Based 

iPhone/IPad with layout that takes advantage of iPad .  ✔ 
✔ 

Dynamic Type Text Sizing (Lists and Buttons)  ✔ 

Landscape / Portrait  ✔ 
✔ 

Styles  4 presets Millions of user specified 
10  2  2  2 
CALC 1  HP 12C Based  HP 10bii Based  HP 17ii+ Based  TI BA Plus Based 

Our design philosophy was to not just copy a hardware calculator, but instead take the best features of each. Then take advantage of the great tools of the iPhone and iPad. Although most developers add features to hardware based calculators, the fact that they are bound to the hardware design make many of the additions awkward.  This is a copy of the HP 12C financial calculator with ALG mode. This does not have the features found on the Platinum and other models with parenthesis and undo. 
The calculation mode does not match the hardware 10bii, but IMHO this is better since it shows the operators and values. This is a copy of HP's entry level financial calculator with additional features. More features are available, but cost extra with an InApp purchase.  This is a copy of HP's high end financial calculator with additional features.  Copy of TI BA. Even uses the TI manual for documentation. We couldn't find any extra features. 
Basic, scientific and financial calculators evaluate expressions that the user enters. Financial calculators also provide solutions where the calculator executes complicated expressions and the user only is required to provide the inputs.
Financial calculators based on one of these popular hardware calculators (HP 12C, HP 10bii, HP 17bii+, and TI BA) dominate the calculator apps in the iTunes Finance category list of top paid apps.
Although this chart was created by the developer of CALC 1, the reported features are easily verified.
We feel a simple chart of features will help users decide which calculator app is best for them. If you know of any errors in this chart, please contact us.