CALC 1 has a HP 12CP reproduction. This page is a guide to the features of CALC 1 from a HP 12CP users perspective.
HP 12C and HP 12C Platinum users will find using CALC 1 very similar to their calculators.
The Time Value of Money with Odd Periods and Simple Interest Calculator and
Time Value of Money with Odd Periods and Compound Interest Calculator
calculator uses periodic interest rates and have the "12x" and "12÷" keys found on the 12C.
Note that the default calculator displayed for new users is the TVM IYR calculator that uses annual interests rates and payments per year. If you prefer the 12C style periodic interest rates, you want either the:
Time Value of Money with Odd Periods and Simple Interest Calculator
Time Value of Money with Odd Periods and Compound Interest Calculator
calculator found on the Focused Calculator list. They treat odd periods differently, similar to the "STO EEX" 'C' status indicator on the 12CP
At the bottom of the page are tables of detailed features.
CALC 1 handles automatic storing and calculating for the N, i, PV, PMT and FV keys in a slightly different way. This is necessary for the CALC 1 Formula Calculators that using solving and the stored value (initial guess) can determine the calculated result.
The Auto STO "AS" annunciator will turn on when you have entered a number to let you know that then number will be stored when you tap the N, I/YR, PV, FV keys. Otherwise the value will be calculated. If there is any question, hold the key down and the hint will tell you if you are storing or calculating. On the 12C, the TVM key will calculate if the previous key was a TVM key. Otherwise it stores the value.
The cash flows, bond, statistical functions are on separate Focused Calculators. The DATE and ΔDATE keys are on these calculator.
There is also the AMORT key, but I highly recommend the Amortization Form Calculator.
There is also the INT key, but also look at the Simple Interest Loan Formula Calculators.
Instead of just one keyboard layout, CALC 1 has separate Focused Calculators. For bond and depreciation calculations CALC 1 has separate calculators. The Bond Calculator has separate storage for the dates so you do not have to enter them every time. Also, the coupon rate and price labeled so you do not have to use the i and PMT keys. The same goes for the Depreciation Calculator. Since the keys are not shared, they can be labeled for the respective calculator, CALC 1 also features additional features for all of the financial functions so you have the best of both worlds.
CALC 1 has one prefix key, the "shift" key. When you tap that key the other key labels are updated.
You can press and hold any key for a hint.
The CALC 1 "del" key will delete the last digit (like the "g" + "" back arrow key on the Platinum model).
This setting is handled automatically and is determined by the region setting on your device.
CALC 1 uses a "+/" key in place of the CHS key.
Use the EE key in place of the EEX key.
The "del" key serves as a backspace and CLx key.
Tap shift to display the
clr m  Clear user memory (az) values.
clr s  Clear the stack.
clr x  clear the x register.
In addition, most calculators will have "clr" keys for that calculator. Financial calculators will typically have a "clr f" key to clear the financial variables and the statistic calculators will have a "clr l" key to clear the statistic lists.
CALC 1 has undo for just about every operation, not just the clearing. With CALC 1 you can use the shake gesture to undo or redo an operation. If shaking the device is not convenient, tap RCL and the operation to undo will be the label of the wide ENTER key. STO will display the available redo operation.
Shake to undo/redo is also available in the List Manager and after pasting keys, calculators or formulas.
CALC 1 supports chain (CHN), algebraic (ALG) and Reverse Polish Notation (RPN) calculation methods.
For the 12C ALG mode 2+3×4 = 20.00. So it is similar to the CALC 1 CHN calculation mode. The CALC 1 CHN mode also supports parenthesis.
In ALG mode the formula is in a separate area than the results so you can view the entire formula.
CALC 1 stores values in variables az using the STO and RCL keys. The STO and RCL keys will insert the variable when entering a formula.
You can also perform storage arithmetic with the "ra" register arithmetic variable.
See the page on CALC 1 Percentage Calculation Keys for calculating percentages.
%T and Δ% work the same on CALC 1 as the 12C.
CALC 1 also has the following Formula Calculators for percentage calculations:
The CHN and ALG calculation modes support the % operator.
The TVM and Bonds Formula Calculators have the DATE and ΔDYS function keys. See CALC 1 Date Keys for more information.
CALC 1 also has the
There is no option for the format for entering dates. CALC 1 uses the ISO 8601 YYYYMMDD format for entering and displaying dates. The Date calculation pages explain the advantages with the YYYYMMDD format with the entry shortcuts.
CALC 1 display options can be set in the Options view. You have the 3 number styles (None, Decimal and Scientific), the number of digits and rows to display. There is also an option for significant digits that is popular with statistics calculations.
CALC 1 has the following calculators for the financial solutions found on the HP 12C:
HP 12C  CALC 1  Comments 

Time Value of Money  Time Value of Money with Odd Periods and Simple Interest Calculator

The Time Value of Money with Odd Periods and Simple Interest Calculator The Financial Time Value of Money I/YR Calculator and Time Value of Money Form Calculator use the annual interest rate and payments per year as done with the HP10b and HP 17. This also allows you to enter the compounding periods per year for cases where the compounding periods are different from the payments. 
Amortization  Financial Amortization Calculator  The Financial Amortization Calculator allows to to set the starting and ending period and has a key to advance to the next periods. There is also no need to reset the "N" or "PV" values if you want to go out of order. The calculations for each set of periods are save in the CALC 1 History. Also see the Amortization Form Calculator. 
Simple Interest  These are a set of Formula Calculators.  
Cash Flows  Financial Cash Flows Calculator  In addition to IRR and NPR, CALC 1 calculates MIRR. Up to 1,000 cash flows that can be easily edited and reordered using the List Manager. 
Percent  Many calculators have %, Δ% (percent change) and %T (percent of total) keys for quick percentage calculations.  
Depreciation  SL, SOYD, DB and DBX with starting month calculations.  
Bonds  CALC 1 has 5 different date basis and 3 frequencies.  
Statistics  Statistics: 1 List Calculator Statistics: 2 List Calculator 
List based statistics for 1 & 2 lists. Up to 1,000 cash flows that can be easily edited using the List Manager. List based statistics can calculate median, min, max that cannot be calculated with calculators that aggregate their statistics like the 12C. 
Curve Fitting  Curve Fitting: LIN Calculator 
Separate calculators for each type of curve fitting. (Linear curve fitting is included with the HP 12C as part of the statistics) 
Dates  Dates Form Calculator 
The TVM and Bond Calculators have date keys for quick date calculations. 
CALC 1  Comments  

Curve Fitting  Curve Fitting: Ln Calculator Curve Fitting: EXP Calculator Curve Fitting: PWR Calculator 
Separate calculators for each type of curve fitting. (Linear curve fitting is included with the HP 12C as part of the statistics) 
Interest Conversion  Effective Interest Rate Formula Calculator  
Profit Margin  Profit Margin Formula Calculator  
Breakeven  Breakeven Formula Calculator  
Currency Conversions  Currency Conversions Form Calculator  This performs conversions from any Focused or Formula calculator by tapping the CALC 1 logo. 
Conversions  Conversions Form Calculator  This performs conversions from any Focused or Formula calculator by tapping the CALC 1 logo. 
We recommend looking at the list of Focused, Formula and Form calculators for a complete list.
There is no programming needed to customize CALC 1. CALC 1 can still be customized without the need to program. See the Customization page for details.