The built-in Windows calculator has come a long way since first being introduced with Windows 1.0 in 1985. It includes different modes, date calculations, and some handy everyday conversions functions. Here’s how you can get the most out of the often overlooked calculator app.

Switching Between Calculator Modes

As you’ll see below, the Calculator does a lot more than add, subtract, multiply, and divide. You can choose from four modes, depending on your needs.

To switch between modes, click the menu button at the top left and then select a mode from the options below.

Here’s what those different modes do.

Standard Mode

The Standard mode is useful for basic math operations like adding, subtracting, multiplying, and dividing, as well as for finding square roots, calculating percentages, and working with fractions. This is probably the mode that most people will feel comfortable with most of the time.

Scientific Mode

Scientific mode expands on the Standard mode, giving you the additional functions you’d find on a typical scientific calculator. In addition to the Standard mode operators, it contains functions like log, modulo, exponent, trigonometric degrees, and SIN, COS, and TAN.

Programmer Mode

This mode is designed for programmers. It adds the ability to switch between different number systems—binary, decimal, hexadecimal, and octal. It also adds new operations for working with logic gates—Or, And, Xor, and Not—and bit shifting—Lsh, Rsh, RoR, and RoL.

Also, Programmer mode lets you switch between Byte (8 bits), Word (16 bits), DWord (32 bits), and QWord (64 bits) and has an option for binary bit toggling.

Date Calculation Mode

The Date Calculation mode is a handy little tool that lets you calculate the difference between two specific dates. This is perfect for figuring out things like how many days old you are or how many days it is until your next vacation.

All you have to do is select the start and end date, and the calculator will determine the months, weeks, and days between the two.

RELATED: How to Perform Date Calculations in Windows Calculator

Converting Measurements

Ever come across a recipe and it calls for milliliters when you want fluid ounces or been shopping online, and all the prices are in Euros? Well, the calculator has you covered for those and quite a few more everyday conversions you might encounter. Some other conversions include temperature, speed (mph to km/h, knots, or Mach), weight and mass, and data storage, to name just a few.

Click the menu button and select a type of conversion from the list in the “Converter” section.

Click the first measurement—this will be the input—and select a unit from the list provided.

Click the second measurement—this will be the output—and select a unit there as well.

Now, enter your measurement, and the calculator will convert it for you. It also shows a few other related conversions along the bottom.

Storing Numbers in Memory

If you use certain numbers a lot and don’t want to plug them into your calculator every single time, storing them into the calculator’s memory helps a lot. It’s a super useful function that’s available on the Standard, Scientific, and Programmer modes. You’ll control the memory functions using the MS, MR, M+, M-, and MC buttons.

Here’s how they work:

  • MS: Save a new number into the memory.
  • MR: Recall the number from memory.
  • M+: Adds together the number in the input box to the most recently stored number. Can also be used from the memory pane if you want to add to a different number in memory.
  • M-: Subtracts the number in the input from the most recently stored number. Can also be used from the memory pane if you want to subtract from a different number in memory.
  • MC: Clears all numbers from your memory storage.
  • M: Displays all current numbers stored in memory.

Using the MR, M+, and M- buttons work much the same way they do on a physical calculator, working with the last number you stored to memory. However, you also have access to any other numbers you’ve stored to memory during your current session. To see them, click the M button with the down arrow to the far right. You can then click any number in your memory to insert it.

If you’d rather have your memory queue always open, resize your window horizontally and it should pop open when it has enough space to show it all.

Calculator History

If you need to take a look at all the calculations you’ve made in your current session, they’re stored conveniently inside the calculator’s history. Calculator keeps the history stored even when you switch modes, but it is erased when you close the Calculator app.

Accessing the History

There are two ways you can access the history inside the app. The first is to click the history button located in the top right corner. This shows you the list of recent calculations. Clicking on anything in the history will load it back into the calculator’s input box.

If you want to keep the history open, resize the Calculator window horizontally and it should pop up when the window is big enough.

Deleting the History

You can delete individual entries from your history or delete the entire history at once.

To delete an individual entry, right-click it and then click the “Delete” command. To delete the entire history, click the little trashcan icon at the bottom right of the pane.

Keyboard Shortcuts

The Calculator app has keyboard shortcuts integrated into it to make things a bit easier for those of us that like to use hotkeys to get around the desktop. To start with, if you have a number pad on your keyboard, make sure NumLock is turned on and then you can use the pad to perform calculations.

Also, there are some other shortcuts you can use. You can find a full list of these shortcuts on the Microsoft Support Windows Keyboard Shortcuts page, but here are a few of the more generally useful ones:

  • Alt+(1-4): Hold down Alt and press any number from one to four to switch to the different calculator modes.
  • Delete: Clear the current input (this works like the CE key on the calculator)
  • Esc: Clear all input (this works like the C key on the calculator)
  • Ctrl+H: Turn history on and off.

And that’s about it—probably more than you ever wanted to know about the Windows Calculator. Still, it’s an underappreciated tool that packs in a lot of useful features.

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Brady Gavin has been immersed in technology for 15 years and has written over 150 detailed tutorials and explainers. He's covered everything from Windows 10 registry hacks to Chrome browser tips. Brady has a diploma in Computer Science from Camosun College in Victoria, BC.  
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