Everyday reference tables
Free unit converters, postal-code formats, country and airport codes, MIME types, and everyday lookup tables — fast, mobile-friendly reference sheets.
Units
- Angle unit conversion Convert between degrees, radians, gradians, turns, arcminutes, arcseconds, milliradians and mils, each with exact degree and turn equivalents for quick maths.
- 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.
- Drill bit size chart Fractional, letter, number and metric drill bits with the closest metric conversion and typical uses — match bits to screws, bolts and taps quickly.
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.
- Airport liquid rules Carry-on liquids: 100 ml/100 g containers in one litre clear bag, duty-free STEB rules, plus medicine, baby food and formula exemptions.
- 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.
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 HTTP headers The 15 most common HTTP headers, their direction (request, response or both), and what each one is for — a quick developer lookup.
- 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.
- Common network ports quick reference TCP/UDP ports for FTP, SSH, HTTP, HTTPS, email and databases, with a plain-English purpose for firewalls and debugging.
- 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.
Daily life
- Bra size conversion chart Convert bra band sizes between US, UK, EU, FR and AU — plus how cup letters shift between systems, so online orders fit first time.
- Emergency numbers by country Police, ambulance and fire numbers for 14 countries — US 911, UK 999, EU 112, Australia 000, Japan 110/119 — and when 112 works.
- Laundry care symbols explained Every laundry care symbol decoded: wash, bleach, dry, iron and dry-clean icons with meanings, so you never shrink a sweater again.
- Dog and cat years to human years Convert dog and cat ages to human years — separate charts for small, medium and large dogs, plus the first-year milestones that matter most.
- Ring size conversion chart Convert ring sizes between US, UK, EU and Japanese scales with inside diameters in mm — measure your finger at home and order the right size.
Health & fitness
- Blood pressure ranges (AHA chart) AHA blood pressure categories with systolic and diastolic ranges — normal, elevated, stage 1 and 2 hypertension and hypertensive crisis, explained.
- Blood sugar (glucose) ranges Blood glucose thresholds for normal, prediabetes and diabetes (fasting and 2-hour) in mg/dL and mmol/L, plus HbA1c % to mmol/mol.
- BMI chart: healthy weight by height BMI healthy-weight ranges for every height from 150 to 195 cm, with the full BMI category table (18.5–24.9 is healthy) and what BMI misses.
- Body fat percentage chart Body-fat percentage categories for men and women — essential, athlete, fitness, average and obese — across adult age groups.
- Body fat percentage categories by sex Body-fat ranges for men and women: essential, athlete, fitness, average and obese categories, age effects, and the most accurate measurement methods.
- Cholesterol level ranges Desirable, borderline and high ranges for total cholesterol, LDL, HDL and triglycerides in mg/dL and mmol/L, with common clinical ratios.
Cars & travel
- Child car seat rules by country Child car seat rules by country: rear-facing limits and booster/height rules for the US, UK, Germany, Sweden, France, Australia and Japan.
- Which side of the road each country drives on Left-driving and right-driving countries for rentals and road trips — the UK, Japan, Australia, India and Thailand drive left.
- EV charging connector types EV charging connectors compared — Type 2 in Europe, CCS1/CCS2, NACS/Tesla in North America, CHAdeMO and GB/T: speeds, regions and which cars use them.
- License Plate Formats by Country (EU Band Guide) Reference table of car license plate layouts by country: typical letter and number formats plus which nations display the blue EU identification band.
- Motor oil viscosity grades explained SAE oil viscosity explained: the W (winter) cold-pumping number and hot grade, with typical uses for 0W-20, 5W-30 and 10W-40.
- Tire size codes explained (205/55R16) Decode any tire sidewall like 205/55R16: section width, aspect ratio, construction, rim diameter, load index and speed rating — with a worked example.
Calendar & money
- Date formats by country (DMY / MDY / YMD) Which countries write dates day-month-year, month-day-year or year-month-day — with examples, so forms, code and bookings never mix up the month and the day.
- Decimal separator by country Which countries use a decimal point versus a decimal comma, with thousands separators and a 1,234.56 vs 1.234,56 example.
- Which countries use the euro Every country using the euro: the 20 eurozone members with adoption years, microstates with agreements, and unilateral users like Kosovo and Montenegro.
- IBAN lengths by country IBAN length and format for 30+ countries — validate international bank details before transfers: DE 22, FR 27, GB 22, NL 18 characters and more.
- Leap years: rules and next dates Which years are leap years and why: the 4/100/400 rule explained, plus the full list of leap years from 2024 to 2100 — including why 2100 is not one.
- Minimum wage rates by country Minimum wage rates by country: US federal, UK National Living Wage, German Mindestlohn and more — approximate monthly USD plus local figures.
Food & drink
- Air fryer time and temperature conversion Convert oven recipes to air fryer settings for fries, chicken, salmon and muffins — usually 20 °C lower heat and about 20% less time.
- ABV of common alcoholic drinks Typical ABV percentages for 30 drinks — beers, wines, sakes, spirits, liqueurs and cocktails — to compare strength across menus and labels.
- Caffeine in drinks chart Caffeine per cup for coffee, espresso, tea, energy drinks and cola — with the 400 mg daily adult limit and safe pregnancy guidance.
- Coffee brewing ratios Golden-ratio coffee brewing: grams per litre/ml for pour-over, French press, espresso, cold brew and moka, with the SCA 1:18 standard.
- How long food keeps in the fridge Fridge (≤4 °C) and freezer storage times for meat, dairy, cooked food and produce — FDA/USDA-based guidance to cut waste safely, with the 2-hour rule.
- Oven temperature conversion (°C, °F, gas mark) Convert oven temperatures between Celsius, Fahrenheit and British gas marks — very slow to very hot, with a formula and German Stufe for EU ovens.