In Productive, there is a field for just about everything, but sometimes you have your unique metric or calculation that isn't available by default.

Luckily, you can use formulas to combine multiple fields into a custom formula field with simple mathematical operations. Note that formula fields are available for all numeric data across Productive!

To add your formula field, click on **Fields** > **Add Formula**.

Creating a new custom formula

1) Begin by assigning a name to your new field.

2) Choose the values you wish to incorporate. Start by typing "@" to display a dropdown menu with available options. Combine these values using the following supported operations:

Addition (+)

Subtraction (-)

Multiplication (*)

Division (/)

Formulas can also be enclosed in brackets for clarity: (A - B) * C.

# Number formats in Productive

When inputting values in custom formulas, it's important to note that **money values are counted in cents**, while **time values are counted in minutes**. This ensures accurate calculations and prevents any misunderstandings with the units being used.

If you are adding a custom formula which will be

**taking into account money values**, the inserted value will be counted in cents.

For example, if you write "**100**", the calculated value will be 1.00, so make sure to add two zeroes if needed. In other words, instead of 100 becoming 1.00, you will need to enter 10000 which will become 100.00.

If you are adding a custom formula which will be

**taking into account time values**, the inserted value will be counted in minutes.

In other words, if you write "100", the calculated value will be 100 minutes, not hours.

**Custom Formula Use Case**

Let's generate a field to showcase the difference between the time we estimated it would take to finish a project and the time we worked and logged in Productive.

The formula we want to use here is Estimated time - Worked time. We'll call our new field "Remaining time" for simplicity.

After inputting the formula, click on "Create Field" to add it to your view.

**Pro tip: Composite Formulas**

In Productive, you can create composite formulas/fields by combining multiple formulas to calculate a single metric.

For example, you can create the "Total Time" field, which is composed of two previously defined formulas "Internal" and "Client".