86 tools and guides in Converter. Pick one and use it right away.
Convert length, weight, temperature, and volume units in real time.
Converter →Instantly convert between cooking measurements — cups, tablespoons (Tbsp), teaspoons (Tsp), milliliters (ml), and fluid ounces (fl oz) — with this free measurement converter.
Converter →Convert a Gregorian (solar) date to the traditional East Asian lunisolar calendar, or a lunisolar date back to the Gregorian date. Supports leap months and shows the sexagenary (gapja) cycle.
Converter →Enter a reference city and time, and instantly see the local time in Seoul, New York, London, Tokyo, and other major cities around the world.
Converter →A free online tool to encode text to Base64, or decode a Base64 string back to plain text. Full Unicode support, including non-ASCII characters.
Converter →Convert spaces, accented characters, and other special characters in a URL into percent-encoding, or decode an already-encoded URL back to plain text. Free URL encoder/decoder.
Converter →Convert between binary, octal, decimal, and hexadecimal in real time, plus support for arbitrary base conversion between base 2 and base 36.
Converter →Instantly translate English text to Morse code, or Morse code back to text, with a free Morse code translator. You can even play it back as sound.
Converter →Compare and convert Korean (mm), US, UK, and EU shoe sizes at a glance with this free shoe size converter. Handy for online shopping and importing from abroad.
Converter →Compare women's and men's tops across US, UK, EU, Korean, and Japanese sizing. A free clothing size conversion chart for shopping online from abroad or while traveling.
Converter →Convert Arabic numbers to Roman numerals, or Roman numerals to Arabic numbers, instantly and in both directions. Supports the range 1–3999.
Converter →Enter a text color and background color to calculate the WCAG 2.1 contrast ratio and see whether it passes AA and AAA accessibility levels.
Converter →Convert between the fuel economy units used around the world — km/L, US mpg, and L/100km — with this free fuel economy unit converter.
Converter →Convert Fahrenheit (°F) and British gas mark temperatures, common in overseas recipes, to Celsius (°C) all at once with this oven temperature converter.
Converter →A free currency converter that converts between the US Dollar, Euro, Japanese Yen and 160+ other currencies using live exchange rates.
Converter →A reference of 25 commonly used web (CSS) color names like Tomato, SlateBlue, and Turquoise, organized by color family with their HEX codes.
Converter →Convert HEX, RGB, and HSL color codes to each other in real time, and automatically generate a tone palette and complementary colors from your chosen color, for free.
Converter →How US clothing and shoe sizing is actually constructed, why the same labeled size fits differently across brands, and rough approximate offsets against UK and EU sizing.
Converter →The everyday cooking conversions people search for mid-recipe — teaspoons to tablespoons, cups to ounces, sticks of butter to grams, and oven temperatures — with the exact ratios behind each one.
Converter →The seven basic Roman numeral symbols, how addition and subtraction rules combine them, worked examples, and where Roman numerals still show up in everyday life.
Converter →A plain-language guide to how digital storage units scale from bits to terabytes, why binary and decimal counting give different numbers, and why a drive never quite matches its advertised capacity.
Converter →How the ISO 216 "A" paper size series works, why A4 is the world standard outside North America, and how it compares with US Letter and Legal sizes.
Converter →A reference table for converting oven temperatures between Fahrenheit, Celsius, and UK gas mark numbers, plus the general heat-level names ("slow," "moderate," "hot") that older recipes use instead of numbers.
Converter →How Base64 turns binary data into printable text, where it typically shows up, and why encoding is fundamentally different from encryption.
Converter →Why screens mix light using RGB (additive color) while printing mixes ink using CMYK (subtractive color), and why the same design can look different on a monitor versus on paper.
Converter →The exact formulas for converting between Celsius and Fahrenheit, a quick mental-math shortcut for estimating on the fly, and why the two scales exist side by side.
Converter →What the built-in named colors in CSS actually are, where the list came from, how many exist, and why relying on hex or RGB values is usually safer for anything beyond quick prototyping.
Converter →The formula that converts a monitor's refresh rate into the time each frame is displayed, why the jump from 60Hz to 144Hz feels bigger than 144Hz to 240Hz, and how refresh rate differs from frame rate.
Converter →How neck circumference translates into a dress shirt collar size in both inch-based (US/UK) and centimeter-based (EU/Asia) systems, how to measure correctly, and why the same labeled size can fit differently across brands.
Converter →Why URLs cannot contain arbitrary characters directly, how percent-encoding converts unsafe characters into %XX sequences based on UTF-8, and common pitfalls like double-encoding and the space-versus-plus confusion.
Converter →A plain guide to the angle units you actually run into — degrees, radians, gradians (gons), arcminutes, and arcseconds — and how they convert into each other.
Converter →How American Wire Gauge (AWG) sizing compares to the metric cross-sectional area (mm²) used across most of the world, and why the two systems do not translate into round numbers.
Converter →The difference between lumens (total light output) and lux (light landing on a surface), how they relate through area and distance, and why lightbulb packaging switched from watts to lumens.
Converter →How points, pixels, millimeters, and em/rem relate to each other in typography, based on the 96dpi web standard, and why the same "size" can look different in print versus on screen.
Converter →How shutter angle relates to shutter speed in video, why the 180-degree rule produces natural-looking motion blur, and how to convert between the two for any frame rate.
Converter →How the standard units of acceleration relate to each other, why "g" is used to describe g-force separately from gravity itself, and where Gal still shows up today.
Converter →How the relative sweetness of common sugar substitutes compares to table sugar, why the conversion ratios are approximate ranges rather than fixed numbers, and why baking with them is not a simple swap.
Converter →How salinity percentage is calculated for pickling and fermentation brines, common reference points like seawater and saturated brine, and why salt should be measured by weight, not volume.
Converter →How Tesla (SI) and Gauss (CGS) relate as units of magnetic flux density, with everyday reference points from Earth's magnetic field to MRI machines, and why both units are still in use.
Converter →What a basis point (bp) means, why finance uses it instead of plain percentages, and how to convert between basis points, percent, and decimal form.
Converter →How the moon's age (days since new moon) relates to its illuminated percentage and named phase, and why the simple approximation differs slightly from precise astronomical calculations.
Converter →How to convert between the fuel-economy units used in different countries — km/L, miles per gallon (MPG), and liters per 100km — and why L/100km behaves differently from the other two.
Converter →How positional number systems work, why computing relies on binary and hex, and practical shortcuts for converting between binary, octal, decimal, hexadecimal, and any base from 2 to 36.
Converter →How the WCAG 2.1 contrast ratio formula works, what the AA and AAA thresholds actually require for normal and large text, and practical ways to fix a color pair that fails.
Converter →What a quoted exchange rate actually represents, why floating exchange rates change constantly, how cross-currency conversion is calculated behind the scenes, and why a converter's number rarely matches your bank statement exactly.
Converter →Where each common pressure unit (Pa, kPa, bar, atm, psi, mmHg, kgf/cm²) comes from, how they relate to one another, and which one shows up in weather reports, tire gauges, medical readings, and engineering specs.
Converter →How square meters, hectares, acres, square feet, and other area units relate to one another, why farmland, real estate, and geography each default to a different unit, and how to sanity-check a conversion.
Converter →How the Kelvin scale describes light color, why "warm" light has a lower Kelvin number than "cool" light, what warm white, neutral white, and daylight ranges mean, and why photographers convert Kelvin to mired.
Converter →What Unix time (the "epoch") actually counts, why seconds and milliseconds formats get mixed up so often, how timestamps relate to ISO 8601 dates, and what the Year 2038 problem is.
Converter →How latitude and longitude work, the difference between DMS and decimal degrees notation, the conversion formula between them, and what each decimal place actually means for real-world precision.
Converter →What torque actually measures, how newton-meters, kgf-based units, and pound-foot/pound-inch units relate to one another, and why mixing up lb-ft and lb-in is one of the most common — and costly — mechanical mistakes.
Converter →How road and ramp slope is expressed as a percent grade, an angle in degrees, or a ratio like 1:12, why they are not linearly related, and where each notation is actually used.
Converter →What calories, joules, watt-hours, and BTUs actually measure, how they convert into each other, and why food labels, physics, and appliance ratings all use different energy units.
Converter →How density units relate to each other, why g/cm³ and kg/L happen to be numerically identical, and when US customary density units like lb/ft³ and lb/gal are used instead of metric ones.
Converter →How band size and cup size are measured separately, why the same cup letter means a different actual size in different countries, and how to read US, UK, EU, French, and Japanese bra sizing side by side.
Converter →Why height is a more reliable sizing guide than age for children's clothing, how US toddler and kids sizing works, how EU height-based numbering compares, and how to convert between them.
Converter →Why the same cup of flour, sugar, or cocoa powder can weigh different amounts depending on how it was scooped, and the approximate gram weights bakers use to convert cups, tablespoons, and teaspoons into grams.
Converter →Why blood glucose is reported in mg/dL in some countries and mmol/L in others, the conversion factor between them, and how to read a number in either unit. Informational only, not medical advice.
Converter →How seconds, minutes, hours, days, weeks, months, and years convert into each other, why months and years do not have a single fixed length, and the approximations commonly used to convert them anyway.
Converter →Why screen sizes are advertised as a diagonal measurement, how to convert that diagonal between inches and centimeters, and how aspect ratio determines the actual width and height of a display.
Converter →