Calculator OS X App

You probably think the Calculator app on your Mac is a bare-bones math calculation app used to quickly multiply, divide, subtract, and add numbers, but it can do many other things that are often overlooked.

Although it’s great at these kinds of things, did you know your OS X Calculator app is also a full-featured unit converter that can convert one form of measurement to another? For example – converting meters to yards, or inches to centimeters.

In this tutorial, we’ll show you how you can use the Calculator app on your Mac to quickly convert a unit of measurement to another.

Stop downloading those third-party unit converting apps!

There are tons of unit conversion apps in the Mac App Store that allow you to convert one type of unit of measurement to other types. Although some are free, many of them are paid, and they’re taking advantage of the fact that you don’t know your Mac already has this functionality built into it.

On the other hand, some of these apps may very well be worth the money, because as you’ll see, the Calculator app doesn’t have every unit of measure known to man, like some third-party conversion apps seem to have. But for the every-day unit converter, the OS X Calculator app does a pretty decent job and has some of the most commonly-converted units of measure you’ll use throughout your daily life.

How to use the calculator app to convert units of measure

Now you probably think I’m going to tell you to remember there are 12 inches in a foot to use the Calculator to convert a unit of measure, but no. There is actually a function built right into the Calculator app on your Mac that has all these formulas built into it already, so you won’t have to remember how many quarts are in a gallon, or how many feet are in a yard, etc.

If you wanted to convert a number of feet to inches, for example, convert 2,847 feet to inches, you would simply follow these easy steps:

1) Launch the Calculator app on your Mac and enter “2847” in the numeric display.

OS X Calculator app convert units of measure 1

2) From the Menu bar, navigate to Convert > Length…

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3) In the Calculator app’s new pop-up menu, make sure “Length” appears under the Convert selection box, “Feet” appears under the From selection box, and “Inches” appears under the To selection box. Then, click on the blue Convert button.

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4) The Calculator app will automatically convert 2,847 to 34,164 to indicate that there are 34,164 inches in 2,847 feet:

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That’s all there is to it! You’ve just used the Calculator app on your Mac to convert one unit of measure to another. You can use any numbers and any units of measure you want, and the steps above will still be the same.

What units of measure are supported?

The OS X Calculator app supports a wide range of units of measure, including those from the following:

  • Area
  • Currency
  • Energy or work
  • Length
  • Power
  • Pressure
  • Speed
  • Temperature
  • Time
  • Volume
  • Weights and masses

As a side note, the Currency function gets its data from Yahoo!, and these numbers need to be updated regularly because currency is subject to change. Your Mac doesn’t keep this up to date automatically, so when you intend to use the currency converter, you need to update the values to the latest known amounts for accuracy.

When you want to do this, just choose Currency from the list of convertible units of measure, and where you see an Update button, the Calculator app will tell you when the values were last updated. Just click on that Update button, and the Calculator app will grab the latest values from Yahoo! so you can have accurate conversions:

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We know, this won’t replace every third-party app

Although it won’t replace every third-party conversion app on the market simply due to the limited unit conversion choices, it does host most of the basics that every-day people are going to use.

If your needs aren’t built into the Calculator app, then by all means go ahead and download a third-party unit conversion app from the Mac App Store.


For quick and easy conversions, just launch the Calculator app on your Mac. It’s great for converting between common units of measure and can be done without installing any third-party software on your Mac.

Also read: How to quickly delete digits in the iOS Calculator app

Did you know the Calculator app on your Mac could convert between different units of measure? Share in the comments below!

  • James Dodd

    You could also just use Spotlight that does everything that the Calculator Convert feature does, but only by typing. Much easier.

  • iPhoneWINS

    or just use google.. much faster

    • :D

      Or even Siri

    • True, however this method will work even when you’re offline.

  • Anonymous

    Yeah i use spotlight as well.

  • iByron

    This is very useful info. It doesn’t seem to show conversions in the “Paper Tape” though. I think that might add to usefulness.

    For me the only reason to buy a converter app is if it lets me enter my own units. I have some proprietary volume units for my workplace that would not be very useful for other people, so asking Apple or a dev to add them it would be really wasteful. It’s much simpler if I can set unit A = 5.5 oz, unit B = 750ml, and unit C = 12 unit B, and unit D = 42 gallons, and then compare the four new units directly rather than making multiple conversions.

  • Martynet

    not bad, but I still prefer the free tool Converto, which is at the top bar.

  • M_Hawke

    Just FYI for you fellow Windows users, the native calculator has this too. Just click on the menu in the upper left corner.

  • crcking

    very useful info

  • Too bad Spotlight still can’t calculate percentages. For example:

    10 + 50% = 15


    • Lol… See this. On which OS are you buddy?

      • Did you even bother reading my comment you supposedly “replied” to??

  • You could also just add a “Unit Converter” widgets in you Dashboard . Much easier.