Simple and unobtrusive unit converter for most needs. It can be used as a regular app window but is also available as menu bar widget, and Today Notification Center widget*. Available in more than 20 languages.
- Categories: Angle, Area, Currency, Data Units, Density, Energy, Fuel Efficiency, Length, Mass, Power, Pressure, Speed, Temperature, Time, Timestamp, and Volume
- Multiple converters are possible in the notification center (available until macOS Catalina 10.15)
- Menu bar widget (requires macOS 10.13 or higher)
- Rates for more than 40 currencies (Sources: Floatrates/Fixer)
- Settings (in menubar) for: light and dark mode; keeping the window on top; thousands separator; decimal places
- Share conversion via mail, messages etc.
- Swapping of units
- Localized to 23 languages: Arabic, Chinese (Simplified), Czech, Danish, Dutch, English, French, German, Greek, Hungarian, Korean, Indonesian, Italian, Japanese, Norwegian, Polish, Portuguese, Romanian, Russian, Spanish, Swedish, Thai, Turkish.
Requires macOS 10.11 (El Capitan) or higher.
* Today widgets with text input fields are not available anymore in macOS 11.0 (Big Sur) and will not show up. They are still available in macOS versions prior to 11.0.
Getting Started & Help
Add widget in notification center (pre macOS Big Sur only)
Open the notification center on your Mac and click on the “Edit” button at the bottom of the view. Then click on the green + button next to the Unit Converter. This is only available until macOS Catalina (10.15) and not in Big Sur (macOS 11) and later.
Add multiple converters in notification center (pre macOS Big Sur only)
Tap on the circled i button and then tap on the green + button (at the bottom of the list) to add more converters. Likewise converters can be deleted.
In order to change the settings you have open the app (if you just use the notification center version, click on the settings icon in the Unit Converter). Go to the “View” menu item to see all settings.
What conversions are available in Euler’s Unit Converter?
Angle: Degree, Arc Minutes, Arc Seconds, Radians, Gradians, Revolutions
Area: Square Kilometer, Square Meter, Square Millimeter, Square Miles, Square Yards, Square Feet, Square Inches, Acres, Ares, Hectares
Currency: AED, AUD, BGN, GBP, BRL, CAD, CLP, CNY, CRC, HRK, CZK, DKK, EUR, GEL, GHS, HKD, HUF, INR, IDR, ILS, ISK, JMD, JPY, KWD, MXN, MYR, NGN, NOK, NZD, PEN, PHP, PKR, PLN, QAR, RON, RUB, SAR, SCR, SGD, ZAR, KRW, SEK, CHF, THB, TRT, TWD, UAH, USD, UYU
Data Units: bit, kbit, Mbit, Gbit, byte, KB, MB, GB, TB, KiB, MiB, GiB
Density: Gram per Cubic Centimeter, Gram per Cubic Meter, Gram per Liter, Gram per Milliliter, Kilogram per Cubic Centimeter, Kilogram per Cubic Centimeter, Kilogram per Liter, Ounce per Cubic Foot, Ounce per Cubic Inch, Ounce per Gallon, Ounce per Gallon US, Pound per Cubic Foot, Pound per Cubic Inch, Pound per Gallon, Pound per Gallon US, Slug per Cubic Foot, Long Ton per Cubic Yard, Short Ton per Cubic Yard
Energy: Kilojoules, Kilocalories, Kilowatt Hours, BTUs, Foot Pounds, Newton Meter
Fuel Efficiency: Liters per 100 Kilometers, Miles per Gallon, Miles per Imperial Gallon
Length: Millimeter, Centimeter, Meters, Kilometers, Inches, Feet, Yards, Miles, Nautical Miles, Light Years, Fathoms, Furlongs, Astronomical Units, Parsecs, Pixel, Points, Pica
Mass: Kilograms, Grams, Ounces, Pounds, Stones, Metric Tons, Short Tons, Carats, Ounces Troy, Slugs
Power: Watts, Kilowatts, Foot Pound Force Min, Foot Pound Force Sec, Metric Horsepower, Horsepower
Pressure: Newtons Per Meter Squared (Pascal), Kilopascals, Hectopascals, Inches of Mercury, Bars, Millibars, Millimeters of Mercury, Pounds per Square Inch
Speed: Meters per Second, Feet per Second, Kilometers per Hour, Miles per Hour, Knots, Speed of Light
Temperature: Celsius, Fahrenheit, Kelvin
Time: Years, Weeks, Days, Hours, Minutes, Seconds, Milliseconds, Microseconds, Nanoseconds
Timestamp: Unix, ISO 8601, RFC 2822, SQL, Core Data
Volume: Cubic Meter, Cubic Feet, Liters, Milliliters, Gallons, FluidDrams, Fluid Ounces, Pints, Quarts, Cups, Tablespoon, Teaspoon
Frequently Asked Questions
Why is the widget not available on macOS 11 (Big Sur) anymore?
Apple decided to remove support to prior macOS 11 widgets entirely. The new widget system does not allow text fields anymore (simply buttons are possible), which makes it useless for this app. They are still available in versions prior to macOS version 11. Since Euler’s Unit Converter version 2.0 a menu bar widget has been added to compensate for this issue.
How often are the currencies updated?
Currencies are provided by Fixer and FloatRates, and updated once a day.
Why the name Euler?
Leonhard Euler (1707 – 1783) was a Swiss mathematician born in Basel, which is also the hometown of the developers.
V2.0.4 – 4th September 2021
Added currency: Icelandic króna (ISK)
- Improved Pica formatting (e.g., 2p3)
- Minor internal improvements
V2.0.3 – 15th May 2021
Added to category Energy: Newton meter
Added currency: Malaysian Ringgit (MYR)
V2.0.2 – 20th February 2021
Added new category: density
Improved handling of preferences changes
V2.0.1 – 19th January 2021
Added currency: Uruguayan Peso
Fixed currency data update in menu bar widget
Minor bug fixing
V2.0 – 1st December 2020
- Added menu bar app (compatible with macOS 11 Big Sur as previous today widgets are not available anymore); use option in preferences to enable/disable
- Minor layout optimizations
- Support Apple Silicon
V1.10 – 8th October 2020
- The last selections for each category in app/widget are now preserved
- Added preferences menu
- Added to length category: Pica
V1.9.5 – 2nd April 2020
- Added to timestamp category: Core Data
- Increased window size
- Minor bug fixes
V1.9.4 – 1st March 2020
- Added to currency category: KWD
- Added to speed category: feet per second
V1.9.3 – 20th December 2019
- Added to currency category: UAH
- Fixed issue to keep unit settings when selecting same category (widget only)
V1.9.2 – 22nd October 2019
- Added to currency category: PKR, NGN
- Added to length category: pixel, points
V1.9.1 – 6th October 2019
- Fixed 24hr bug in ISO 8601 conversions (timestamps category)
V1.9 – 12th September 2019
- Added new category “Timestamp” (converts between unix, ISO 8601, RFC 2822, and SQL formats)
- Added currency: Georgian Lari (GEL)
- Improved translations
V1.8.1 – 8th August 2019
- List in widget can now be edited (to change order of converters)
- Improved darkmode support
- Improved touchbar support
V1.8 – 22nd July 2019
- Widget now supports multiple parallel conversions
- Added currency SCR, length units
V1.7 – 25th February 2019
- Added currencies CRC, JMD, PEN
- Fixed service for alternative currency source
V1.6 – 7th October 2018
- Added possibility to swap units for even easier conversions
- Fixed some layout issues
V1.5 – 20th September 2018
- Support for macOS Dark Mode
- Added currency: Ghanaian Cedi
V1.4.2 – 29th June 2018
- Added “Data Units” category
- Added to category “Volume”: Imperial Gallons
V1.4.1 – 4th April 2018
- Added currency: New Taiwan Dollar
V1.4 – 31th January 2018
- Added “Time” category
V1.3 – 26th April 2017
- Added additional currency source with AED, CLP, QAR, SAR
- Increased country flags size
V1.2 – 7th April 2017
- Added localizations for: Indonesian, Romanian
- Add touch bar support for settings
- Fixed currency loading timeout
V1.1 – 25th March 2017
- Added localizations for: Arabic, Chinese (Simplified), Czech, Danish, Dutch, Greek, Hungarian, Korean, Polish, Russian, Thai, Turkish
V1.0 – 19th March 2017
- Initial Version