poster-design-utils

A collection of utility functions for poster and graphic design calculations.

Create stunning AI-powered posters at poster.sh

Installation

npm install poster-design-utils

Features

• Paper size constants (ISO A-series, US sizes, social media dimensions)
• Unit conversions (mm, inches, pixels)
• Color conversions (HEX, RGB, CMYK)
• DPI calculations for print and web
• Aspect ratio calculations
• File size estimation

Usage

const posterUtils = require('poster-design-utils');

// Get poster dimensions in pixels
const a3Poster = posterUtils.getPosterDimensions('a3', 300, 'portrait');
console.log(a3Poster);
// { width: 3508, height: 4961, name: 'A3', orientation: 'portrait' }

// Get Instagram story dimensions
const story = posterUtils.getPosterDimensions('instagram_story');
console.log(story);
// { width: 1080, height: 1920, name: 'Instagram Story', orientation: 'portrait' }

// Convert mm to pixels
const pixels = posterUtils.mmToPixels(210, 300); // A4 width at 300 DPI
console.log(pixels); // 2480

// Color conversions
const rgb = posterUtils.hexToRgb('#ff5733');
console.log(rgb); // { r: 255, g: 87, b: 51 }

const cmyk = posterUtils.rgbToCmyk(255, 87, 51);
console.log(cmyk); // { c: 0, m: 66, y: 80, k: 0 }

// Get aspect ratio
const ratio = posterUtils.getAspectRatio(1920, 1080);
console.log(ratio); // '16:9'

// Estimate file size
const fileSize = posterUtils.estimateFileSize(3508, 4961, 24, 0.1);
console.log(fileSize); // { bytes: 2088670, kb: 2040, mb: 1.99 }

Available Paper Sizes

Print Sizes (mm)

• a0 - A0 (841 × 1189 mm)
• a1 - A1 (594 × 841 mm)
• a2 - A2 (420 × 594 mm)
• a3 - A3 (297 × 420 mm)
• a4 - A4 (210 × 297 mm)
• a5 - A5 (148 × 210 mm)
• a6 - A6 (105 × 148 mm)
• letter - US Letter (216 × 279 mm)
• legal - US Legal (216 × 356 mm)
• tabloid - Tabloid (279 × 432 mm)

Social Media Sizes (pixels)

• instagram_square - 1080 × 1080
• instagram_portrait - 1080 × 1350
• instagram_story - 1080 × 1920
• facebook_post - 1200 × 630
• twitter_post - 1200 × 675
• youtube_thumbnail - 1280 × 720
• linkedin_post - 1200 × 627

API Reference

Unit Conversion

• mmToPixels(mm, dpi) - Convert millimeters to pixels
• pixelsToMm(pixels, dpi) - Convert pixels to millimeters
• inchesToPixels(inches, dpi) - Convert inches to pixels
• pixelsToInches(pixels, dpi) - Convert pixels to inches

Poster Dimensions

• getPosterDimensions(size, dpi, orientation) - Get dimensions for a paper size

Color Conversion

• hexToRgb(hex) - Convert HEX to RGB
• rgbToHex(r, g, b) - Convert RGB to HEX
• rgbToCmyk(r, g, b) - Convert RGB to CMYK (for print)

Utilities

• getAspectRatio(width, height) - Calculate aspect ratio
• estimateFileSize(width, height, bitDepth, compressionRatio) - Estimate file size
• getRecommendedDpi(useCase) - Get recommended DPI for use case

Related

• poster.sh - AI Poster Generator
• Create stunning posters with AI in seconds

License

MIT