Miniscale

A tiny package for working with modular scale, that is most useful for meaningful typography.

Installation

npm install miniscale

How to use

Set up your scale with a base (font) size, and a ratio:

import { scale } from 'miniscale';
const ms = scale(16, 1.125);

Calculate certain steps, sizes and ratios, while walking up or down on the scale:

// Two steps up from the base
ms(2)         // -> { index: 2, value: 20.25, ratio: 1.265625 }
ms(2).value   // -> 20.25

// One step down
ms(-1).ratio  // -> 0.8888888888888888

// Get the base
ms(0)         // -> { index: 0, value: 16, ratio: 1 }

Values with units

For stylesheets px, rem and em conversion comes handy:

import { withUnits, scale } from 'miniscale'

const ms = withUnits(scale(16, 1.125))

ms(2).px   // -> "20.25px"
ms(2).rem  // -> "1.265625rem"
ms(2).em  // -> "1.265625em"

Multiplier (for spacing)

The ms() function accepts a second parameter: a multiplier value. Typography-based spacing is a good use case for this feature:

// Here we choose base font size as main spacing unit
const space = (units) => ms(0, units)

// Then we can include space as number of units:
space(1).px   // -> 16px
space(5).px   // -> 80px
space(2).rem  // -> 2rem

Generating a scale as array

The scale() function calculates the values on the fly. If you need a static array of the steps, you can use the scaleArray() function. It generates an array in the range of min and max, that contains all values of each step.

import { scale, scaleArray } from 'miniscale'
const steps = scaleArray(scale(16, 1.125), { min: 14, max: 36 })

/*
 *[ { index: -1, value: 14.222222222222221, ratio: 0.8888888888888888 },
 *  { index: 0, value: 16, ratio: 1 },
 *  { index: 1, value: 18, ratio: 1.125 },
 *  { index: 2, value: 20.25, ratio: 1.265625 },
 *  { index: 3, value: 22.78125, ratio: 1.423828125 },
 *  { index: 4, value: 25.62890625, ratio: 1.601806640625 },
 *  { index: 5, value: 28.83251953125, ratio: 1.802032470703125 },
 *  { index: 6, value: 32.43658447265625, ratio: 2.0272865295410156 } ]
 */

The withUnits() function can be used here too:

const steps = scaleArray(withUnits(scale(16, 1.125)), { min: 14, max: 36 })
console.log(steps[2].px)  // -> "18px"
console.log(steps[2].rem)  // -> "1.125rem"