Everyday reference tables
Unit converters, postal formats, country codes, MIME types, and more lookup tables.
Units
- Area unit conversion Convert square meters, hectares, acres, square feet, and square miles instantly, with formulas, worked examples, and a free converter & printable chart.
- Clothing size conversion (approx) Rough mapping of letter sizes (XS–XXL) across US, UK, EU, and CN clothing labels, including men’s shirt neck and pant waist measurements, too.
- Cooking measurement conversion Convert teaspoons, tablespoons, cups, butter sticks, and oven temperatures between US recipe units and metric — with flour and sugar cup weights.
- Data storage units (KB MB GB TB) Bits, bytes, and decimal vs binary prefixes used by disks and OS displays, from kilobytes up to petabytes — quickly see which unit fits your case.
- Energy and power units Convert between joule, calorie, kWh, BTU, watt, and horsepower — handy for home appliances, fitness, and science. Check and compare values fast.
- Fuel economy conversion (MPG ↔ L/100 km) Convert US MPG and UK MPG to L/100 km and back — exact 235.215 / 282.481 constants, a 10–50 MPG chart, and an instant converter for any value.
Places & codes
- Major airport IATA codes Three-letter IATA codes for the most-searched international airports worldwide, each listed with the city and country that the airport code serves.
- International dialing codes by country International dialing codes for 38 countries with example local numbers — find any +code instantly and call abroad with the right prefix order.
- Country capitals (selected) Quick reference to the capitals of frequently searched countries and regions, with multi-capital cases noted — use Ctrl+F to find any country fast.
- Currency codes (ISO 4217) ISO 4217 currency codes with symbols and minor units for 30+ major currencies — look up any code like USD, JPY or EUR instantly and confidently.
- ISO country codes (alpha-2 / alpha-3) ISO 3166-1 alpha-2 and alpha-3 codes for the world's countries and key regions, in one quick reference for forms, checkout flows and localization.
- Postal code formats by country Postal code and ZIP code formats by country and region: common patterns, lengths, and examples. Scan the table or use Ctrl+F to find a country.
Web & files
- ASCII printable characters Full ASCII table with decimal, hex and binary codes, control-character names, and printable symbols — look up any character code instantly online.
- Common MIME types Content-Type values for web pages, documents, images, audio, and video — with the file extensions they usually pair with. Pick the right header every time.
- CSS size units (px rem em vh) When to use px, rem, em, %, vw/vh and other CSS length units — quick guidance on each. Pick the right CSS unit for your next layout in seconds.
- Common file extensions What popular file extensions usually mean on the desktop and the web — from .pdf and .zip to .exe and .svg. Identify any file instantly at a glance.
- HTML character entities Common HTML entities for symbols, punctuation, and whitespace, with their entity names. Copy the code you need without hunting through reference tables.
- HTTP status codes quick reference Common HTTP response status codes with short, plain-English meanings for 200, 404, 500 and more. A quick reference for API development and debugging.