Unix Timestamp Converter
Unix time ⇄ human dates, seconds or millis.
Converters & Calculators
Units, timestamps, numbers & everyday maths.
Number Base Converter
Convert numbers between any base 2–36.
Roman Numeral Converter
Numbers ⇄ Roman numerals, 1 to 3999.
Data Size Converter
Bytes, KB/MB/GB and KiB/MiB/GiB, side by side.
Percentage & VAT Calculator
Percentages, percent change and VAT in one place.
BMI Calculator
Body Mass Index from weight and height.
Aspect Ratio Calculator
Simplify ratios and find missing dimensions.
Age Calculator
Exact age in years, months, days and totals.
Tip & Bill Splitter
Split a bill and tip evenly across the table.
Loan Calculator
Monthly payment, total cost and interest.
Compound Interest Calculator
Grow savings with interest and contributions.
Download Time Calculator
How long a download takes at a given speed.
Running Pace Calculator
Pace per km and mile, plus speed, from a run.
Unit Converter
Length, mass, area, volume and temperature.
Timezone Converter
Convert a time between any two time zones.
Physics Unit Converter
Speed, pressure and energy unit conversions.
Cooking Measurement Converter
Cups, spoons, ml and ounces for recipes.
Fuel Cost Calculator
Estimate the fuel cost of any trip.
Acceleration Converter
Convert g, m/s², ft/s² and more.
Angle Converter
Convert degrees, radians, gradians and more.
Clothing Size Converter
Convert clothing sizes between US, UK, EU and IT.
Coin Counter
Tally a jar of coins to an exact total.
Currency Converter
Offline currency maths with an editable rate table.
Density Converter
Convert density between metric and imperial units.
Flow Rate Converter
Convert between L/min, m³/h, gpm, cfm and more.
Force Converter
Convert between newtons, pounds-force, kgf and more.
Frequency Converter
Convert hertz, kHz, MHz, GHz, rpm, rad/s and bpm.
Fuel Economy Converter
Convert MPG, km/L and L/100km instantly.
Illuminance Converter
Convert lux, foot-candles, phot and more.
Luminance Converter
Convert any colour to its luminance and contrast ratio.
Number to Words
Spell any number out in plain English.
Paper Size Reference
Look up paper sizes in mm, inches, points and pixels.
Power Converter
Convert watts, horsepower, BTU/h and more.
PPI Density Calculator
Find a screen's pixels-per-inch and dot pitch.
Resolution Converter
Pixels to aspect ratio, megapixels and standards.
Ring Size Converter
Convert ring sizes between US, UK, EU and Japan.
Shoe Size Converter
Convert shoe sizes between US, UK, EU and cm.
Torque Converter
Convert between N·m, lb·ft and more.
Words to Number
Turn number words into digits instantly.
About Converters & Calculators
Convert units, timestamps, number bases and everyday quantities with instant, in-browser calculators. Turn a Unix timestamp into a human-readable date (and back), convert between metric and imperial units, translate numbers between binary, decimal and hex, work out cooking measures, data sizes, Roman numerals and more. Each converter updates as you type, shows its working where the maths is not obvious, and runs entirely on your device — no uploads, no ads chasing you, no waiting on a server. These are deliberately small, fast pages designed to answer one question and get out of your way.