Using Math in Token Values

Tokens Studio supports math equations to calculate the Value of a Token.

This is a popular approach to a create scales for typography, spacing, size, or dynamically calculate the radius of a focus ring (pictured above).

Combining math equations with referenced to another Token can create a flexible and powerful design system.

Token Types compatible with math

All Token Types that accept numeric values can use math equations to calculate their value in Tokens Studio.

When you apply a Token with a math equation as its value, the Plugin applies the resolved value to the corresponding property in Figma.

Select a card to jump to its technical docs.

Number variables in Figma doesn't support Math equations

This means when you export a Token with math in its value as a Variable in Figma:

You won't see the references or equations.
The plugin sends the resolved value of the equation to Figma as a Number Variable.

Possible Values

Token Values written as equations can include hard-coded number values and references to other Tokens.

For example, if you want spacing.lg to be twice as large as spacing.md you can write an equation to calculate its value:

{spacing.md} * 2

Or, you can replace the multipler with a reference to another Token named scale.multiplier

{spacing.md} * {spacing.multipler}

Syntax

The syntax for writing a math equation varies based on the kind of equation you are writing.

Simple math equations can be written with or without brackets.

For example, 8 * 8 and (8 * 8) will both resolve to 64

Complex formulas require spaces between operators to ensure the Tokens can be transformed correctly using Style Dictionary.

For example: 8 * 8 will transform as expected 8*8 will not.

Looking for more complex formulas supported in the Plugin?

Known limitations

Working with math in the plugin can be a powerful workflow enhancement, but there are some limitations to be aware of.

Multi-value Tokens won't resolve

The plugin supports Tokens with more than one value. When these Tokens are referenced in a math equation, the plugin can not resolve the equation because it doesn't know how to interpret the value.

Units in equations

Referencing Tokens in our math equations that have values that contain units can lead to unexpected results.

This is because the math package we use can resolve equations with units, as long as the units aren't mixed.

For example:

A Token named size-2 with a value of 1.5rem
A Token named density-default with a value of 2px

When both Tokens are included in a math equation written as:

{size-2} + {density-default}

The equation can't be resolved because the Tokens referenced contain a mix of rem and pixel units. If both Tokens have the same units, or are unitless, the equation would resolve as expected.

Workarounds

lineHeights = {lineHeights-calc-body-default}%
fontSize = {scale-rem-md}rem

Equations to try

Here are some math equations used by our team.

Round to the nearest whole number

When using multipliers that aren't a whole number, you can use a rounding function to calculate values that don't include decimals, because a spacing value of 12.11px might not be ideal.

To round to the nearest whole number, you can put our equation inside the roundTo function.

For example, if sizing.sm has a value of 2

roundTo({sizing.sm} * 1.33, 0)

2 * 1.33 = 2.66

Will calculate a resolved value of 3

Create a percentage from a unitless number

For example, the Number Token called lineHeights-unitless.heading.relaxed with a value of 1.5 would be written in a Line Height Token as:

{lineHeights-unitless.heading.relaxed} * 100%

Which calculates a resolved value of 150%

Convert unitless numbers to rem

This equation requires having a Token which defines the value of 1 rem, and adjusting the Tokens Studio plugin settings to reference this Token as the value for "base font size".

In this example, there is a