Use Org mode as an Inline Calculator

If you want to perform some simple calculations you can simply use an Org table and a calc formula.

Let's say you want to calculate the area of a circle. You can do it like this:

| 3.14 | 10 | := $1 * $2^2 |

Which gives you:

There is no need to add a table header. However, in some cases, and particularly for future reference it can be a good idea to add it for clarity. Like so:

| pi   | Radius | Area         |
|------+--------+--------------|
| 3.14 | 10     | := $1 * $2^2 |

Which gives:

#Example - Consultant Income

| *Expected Income*          |                |
| Gross Salary Wanted        | 100000         |
| Health Insurance           | :=0.07 * @2$2  | 
| Pension Plan               | :=0.15 * @2$2  | 
| Total Revenue              | :=vsum(@2..@4) |
| *Hourly rate*              |                |
| Unpaid vacation days       |  20            |
| Public holidays + weekends |  120           |
| Work days per year         | :=365-@7-@8    |
| Work hours per year        | :=@9 * 8       |
| Rate needed                | :=@2 / @10     |

The above calculations gives:

Using variables - Notepad Calculations

It's also possible to use variables to easier refer to data in a cell. Instead of refering to cells by using the row and column specifications (eg. @2$2), you can use a variable name defined in the column to the right of the value cell.

This would result into something similar to a Soulver notepad.

Below is the same example as above, but with variables:

| *Expected Income*         |                               |  
| Gross_Salary_Wanted       | 100000                        | 
| Health_Insurance          | :=0.07 * Gross_Salary_Wanted  |  
| Pension_Plan              | :=0.15 * Gross_Salary_Wanted  | 
| Total Revenue             | :=vsum(@2..@4)                |
| *Hourly rate*             |                               |
| Unpaid_vacation_days      |  20                           |
| PublicHolidaysAndWeekends |  120                          |
| Work_days_per_year        | :=365 - Unpaid_vacation_days - PublicHolidaysAndWeekends  |
| Work_hours_per_year       | :=Work_days_per_year*8        |
| Rate needed               | :=Gross_Salary_Wanted/Work_hours_per_year |

And here is the result which is more or less the same as before except for the variable names used:

Please note that variable names can only consist of upper and lower case letters and underscore (_).