RPN Carpenter's Calculator

This Carpenter's Calculator is a Reverse Polish Notation (RPN) calculator, typically an engineering or financial calculator that uses postfix notation. However, this calculator is designed for carpenters and builders, and includes functions specific to construction calculations such as rafter lengths, angles, stair calculations, and more. It also includes standard mathematical functions and basic arithmetic operations. The RPN input method allows quick, efficient calculations without parentheses, making it ideal for on-site use where speed and accuracy are important. Example calculations and instructions for using the various functions of the Carpenter's Calculator are provided below.

I've used the HP 48g & HP 50g calculator since the the 1980's for rafter calculations. So, I designed this calculator to have a similar feel and functionality to those calculators, but with a more modern interface and additional functions specific to carpentry and construction.

It has a built-in Rafter key that displays the calculations from the input key: Pitch, Rise, Run, or Diagonal. Also, the Plan Key is used to calculate plan angles from two known roof pitches. As well as an Irregular key, to calculate the rafter lengths and angles for Irregular Hip Roofs. Or use the Radius button to enter the width and height of the Arch to calculate the Radius for the Arch. Or use the Miter button to enter the Crown Molding spring angle and wall angle to see the Crown Molding Miter and Saw Bevel angles. Or use the Stair button to enter the Total Height of the stairs to display the different riser height-number risers combinations.

For RPN Usage:
Enter a number, then press the enter key several times, each time you press the enter key the number will be added to the stack. Then press the + key to add the numbers together. Or use the - key to subtract, the * key to multiply, and the / key to divide. The calculator will always operate on the top two numbers on the stack.
For example, to add 3, 4, and 5 together:
Enter 3, then press the enter key (3 is now on the stack)
Enter 4, then press the enter key (4 is now on the stack above 3)
Enter 5, then press the enter key (5 is now on the stack above 4)
Now press the + key (5 and 4 are added together to make 9, which is now on the stack above 3)
Now press the + key again (9 and 3 are added together to make 12, which is now the only number on the stack)
You can also scroll up the stack to see previous calculations and results. The stack stores the last 100 numbers entered or calculated, allowing you to easily reference and reuse them in future calculations.
Select a number on the stack, and it will be copied to the input area, allowing you to use it in a new calculation.