# Free Online Calculator - Basic Arithmetic, Percentages, and More

### About the online calculator

Explore our **free online calculator** for essential arithmetic operations. This
user-friendly calculator is
compatible with both desktop and mobile devices, featuring large keys for ease of use. Whether
you're a student
or professional, this simple online calculator is ideal for your everyday calculations.

Our browser extensions for Chrome and Microsoft Edge add a convenient toolbar icon. Plus, the calculator automatically saves your last calculation, allowing you to close and reopen it without losing your work.

### Key Features:

In addition to the browser extension, our online calculator is available as an embeddable javascript widget, free for use on your web page. Use this page on your mobile device to experience a seamless app-like interface. Save it to your Home Screen, and it will function like a dedicated app. Your previous calculations are readily accessible. Access a history of your last ten calculations. The desktop version supports keyboard and number pad input. Easily copy results from the display to your clipboard.

### Video Guide: Using the Online Calculator for Percentages:

Watch our instructional video to learn how to use the online calculator effectively. The video covers fundamental calculator operations and provides tips on calculating percentages, making it suitable for any basic calculator user.

### Basic Keys (and Keyboard Shortcuts):

Master the essential keys you'll use frequently, whether using your keyboard or the on-screen keys for calculations.

- Number Pad (0-9) for Number Entry
- Equals (= or Enter)
- Copy to clipboard (Ctrl-c)
- Clear ("C")
- DEL (Delete or Backspace) key to remove the last character
- Divide (/) for division
- Multiply (*) for multiplication
- Minus (-) for subtraction
- Plus (+) for addition
- Plus/Minus (+/-) (F3)
- Decimal point (.)
- Square (x²)
- Fraction (⅟x)
- Parentheses for controlling calculation order

### How to calculate percentages

The Percent (F1) key is invaluable for calculating discounts and taxes on items. For instance, if you're shopping and want to determine the tax on a $20 item with a 12% tax rate, enter "12%20" to find that the tax amounts to $2.40. To calculate the total cost, simply use the addition key: "20+12%" yields $22.40.

For discounts, like a 20% store-wide reduction, key in "20-20%" to find the reduced price, then add the tax if applicable. For example, "20-20%+12%" results in a final cost of $17.92.

### How to Calculate the Square of a Number

The Square (x²) key multiplies a number by itself. For instance, entering "9²" equals 81, as 9 multiplied by 9 equals 81.

### How to Calculate the Square Root of a Number

The Square Root (F2) key calculates the square root of a number, which, when multiplied by itself, yields the original number. For example, "9√" equals 3, or "3+9√" equals 9.

### How the Fraction Key Works

The Fraction (⅟x) key, also known as the reciprocal key, generates a fraction with "1 over x." For instance, entering "⅟4" results in 0.25, as 1 divided by 4 equals 0.25.

### How to Use the Plus/Minus (+/-) Key

The Plus Minus (+/-) key converts a value from positive to negative or vice versa.

**How to Use Parentheses in Calculations:**
Parentheses control the order of calculations. Use them to ensure the desired sequence of operations.
For instance, to add 2 and 3 before multiplying by 2, input "(3+2)*2," which yields 10, instead of 8.

### Working with Decimals

For calculations involving decimal numbers, use the Decimal point (.) key. For example, "10.5+6" equals 16.5.

### Quick Tip

To convert a percentage to a decimal, divide by 100. For instance, 35% is equivalent to 0.35 (35/100).

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