Converters
Fast converters: length, weight, volume, area and speed units, temperature, colors and image pixel measurements.
Tools — Converters
cm to pixels calculator
Calculate how many pixels you need for a final size in cm or inches at any PPI/DPI, with aspect ratio checks for photo printing.
Pixel to cm converter
Convert image pixels to cm, mm or inches using PPI/DPI. Select an image locally to read dimensions without uploading it.
Temperature Converter
Convert temperatures between Celsius, Fahrenheit and Kelvin instantly.
Color converter
Convert colors between HEX, RGB and HSL instantly with a live picker.
Length converter
Length converter (cm, m, inches, feet, miles). online converter.
Weight converter
Weight converter (kg, g, pounds, ounces, stone). online converter.
Volume converter
Volume converter (litres, mL, gallons, cups, pints). online converter.
Speed converter
Speed converter (km/h, mph, m/s, knots). online converter.
Area converter
Area converter (m², ft², acres, hectares). online converter.
Aspect ratio calculator
Work out the aspect ratio (16:9, 4:3…) from a width and height in pixels. Instantly.
Energy converter
Convert energy between joules, kilojoules, calories, kilocalories, watt-hours, kWh and BTU. Instantly.
DPI / PPI calculator
Work out DPI/PPI from pixels and physical size, and check whether the resolution is good enough to print.
Image resize calculator
Work out the new width or height while keeping the image’s aspect ratio, plus the scale in %. Instantly.
Data storage converter
Convert data storage between bits, bytes, KB, MB, GB, TB and the binary KiB, MiB, GiB, TiB. Instantly.
Pressure converter
Convert pressure between pascals, kPa, bar, psi, atm, mmHg and Torr. Instantly, in your browser.
Power converter
Convert power between watts, kilowatts, megawatts, horsepower (hp), metric PS, BTU/h and kcal/h. Instantly.
Angle converter
Convert angles between degrees, radians, gradians, turns, arcminutes and arcseconds. Instantly.
Frequency converter
Convert frequency between hertz, kHz, MHz, GHz and rpm. Instantly, in your browser.
Density converter
Convert density between kg/m³, g/cm³, g/mL, kg/L, lb/ft³ and lb/gal. Instantly, in your browser.
Roman numeral converter
Convert numbers to Roman numerals and back (1–3999). Free, instant, in your browser.
Fuel economy converter
Convert fuel economy between mpg (US), mpg (UK), L/100km and km/L. Free, instant, in your browser.
Download time calculator
Estimate how long a download takes from a file size (MB) and your connection speed (Mbps). Free and instant.
Fuel cost & consumption calculator
Work out your real fuel consumption (L/100km), trip cost and range on a full tank from distance and litres used. Free.