Last updated: February 2026

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Free Full Screen Calculator Online

Large display calculator for easy calculations. Free, no download, works on all devices. Use your keyboard or click the buttons.

M
0
M
0

Quick Percentage Calculator

Calculate percentages quickly with these common operations.

What is X% of Y?

What is % of ?

X is what % of Y?

is what % of ?

Increase/Decrease by Percentage

by %
0

⌨ Keyboard Shortcuts

Use your keyboard for faster calculations. All shortcuts work with the standard calculator mode.

0-9
Number keys
+
Addition
-
Subtraction
* or ×
Multiplication
/ or ÷
Division
Enter or =
Calculate result
Escape or C
Clear all
Backspace
Delete last digit
.
Decimal point
%
Percentage

How to Use This Full Screen Calculator

Basic Calculations

  1. Enter numbers by clicking the number buttons or typing on your keyboard
  2. Choose an operation (+, -, ×, ÷) by clicking the operator buttons
  3. Enter the second number
  4. Press = (equals) or hit Enter to see the result
  5. To start a new calculation, press C (Clear)

Using Memory Functions

The memory function allows you to store a value and use it later in calculations:

  • M+ (Memory Add): Adds the current display value to memory
  • M- (Memory Subtract): Subtracts the current display value from memory
  • MR (Memory Recall): Shows the value stored in memory
  • MC (Memory Clear): Clears the memory (sets it to 0)

Examples

Calculation Button Sequence Result
25 + 17 2 → 5 → + → 1 → 7 → = 42
100 - 35 1 → 0 → 0 → - → 3 → 5 → = 65
12 × 8 1 → 2 → × → 8 → = 96
144 ÷ 12 1 → 4 → 4 → ÷ → 1 → 2 → = 12
15% of 200 2 → 0 → 0 → % → 1 → 5 → = 30

Why Use This Free Online Calculator?

Full Screen Display

Large, clear numbers that are easy to read. Perfect for users who prefer bigger text or have visual impairments.

Works Everywhere

Use on your phone, tablet, laptop, or desktop computer. Responsive design adapts to any screen size.

Completely Free

No hidden costs, no signup required, no downloads needed. Just open and calculate.

Instant Results

Get answers immediately. No waiting for page loads or processing. Results appear instantly.

⌨ Keyboard Support

Use your keyboard for faster calculations. All standard keys work intuitively.

Memory Functions

Store values in memory for complex calculations with M+, M-, MR, and MC buttons.

Calculator Tips for Better Results

  • Use brackets mentally: Calculate complex expressions in parts. Do multiplication and division before addition and subtraction
  • Check your work: For important calculations, enter the numbers in a different order to verify
  • Use memory for running totals: When adding many numbers, use M+ to keep a running total
  • Clear before new calculations: Press C to ensure you're starting fresh
  • Use 00 for large numbers: The 00 button saves time when entering hundreds or thousands
  • Double-check decimals: Make sure the decimal point is in the right place before calculating

Professional Calculator Tips for Everyday UK Scenarios

While smartphone calculators handle basic sums, a full-screen scientific calculator is invaluable for more complex real-world tasks that UK residents encounter regularly. Here are practical scenarios where having a proper calculator makes all the difference.

VAT and Business Calculations

The standard UK VAT rate is 20%, but calculating VAT-inclusive and VAT-exclusive amounts trips up many people. To find the VAT amount from a gross price, divide by 6 (not multiply by 0.2). For example, if an item costs £120 including VAT, the VAT portion is £120 / 6 = £20, and the net price is £100. For the reduced rate of 5% (applicable to domestic energy and children's car seats), divide the gross price by 21. Using the memory function (M+, MR) lets you store running totals when processing multiple invoices or expense claims for your Self Assessment tax return.

Mortgage and Loan Quick Checks

Before committing to a mortgage offer, a quick calculation can reveal the true cost. UK mortgage rates are quoted annually but charged monthly, so divide the annual rate by 12 to get the monthly rate. For a rough monthly payment estimate on a repayment mortgage, you can use the formula: loan amount multiplied by the monthly rate, divided by (1 minus (1 plus monthly rate) to the power of negative total months). The power function (x^y) on a scientific calculator handles this easily. For a £250,000 mortgage at 4.5% over 25 years, this works out to approximately £1,390 per month.

Unit Conversions for Home Improvement

UK home improvement involves a mix of imperial and metric measurements. Timber from merchants is sold in metric lengths, but many older UK homes have rooms measured in feet and inches. Converting between the two requires multiplying feet by 0.3048 to get metres. For flooring calculations, multiply room length by width to get square metres, then add 10% for wastage. A 12ft x 14ft room equals 3.66m x 4.27m = 15.63 square metres, meaning you'd need approximately 17.2 square metres of flooring to account for cuts and waste.

Frequently Asked Questions

How do I use a full screen calculator online?

Simply open the calculator in your web browser. Click the number buttons to enter values, use operation buttons (+, -, ×, ÷) for calculations, and press equals (=) to see results. Use Clear (C) to start a new calculation or the backspace button (←) to delete the last digit. You can also use your keyboard for faster input.

Can I use this calculator on my mobile phone?

Yes! This full screen calculator is fully responsive and works perfectly on all devices including smartphones, tablets, laptops, and desktop computers. The large buttons are designed to be easy to tap on touchscreens, making it ideal for mobile use.

Is this online calculator free to use?

Yes, this calculator is completely free to use. There's no signup required, no download needed, and no hidden costs. You can use it as many times as you want for all your calculation needs - whether that's quick maths, checking receipts, or homework help.

What calculations can this full screen calculator do?

This calculator performs basic arithmetic: addition (+), subtraction (-), multiplication (×), division (÷), and percentages (%). The power mode also includes squares (x²), cubes (x³), square roots (√), and custom powers (xⁿ). It also includes memory functions (M+, M-, MR, MC) to store values for later use.

How do I calculate percentages?

Use the Percentage mode tab for easy percentage calculations. For "What is 15% of 200?", the answer is 30. For "30 is what % of 200?", the answer is 15%. You can also increase or decrease values by a percentage - for example, £100 increased by 20% equals £120.

Can I use keyboard shortcuts?

Yes! You can use your keyboard for faster calculations. Number keys (0-9) for digits, +, -, *, / for operations, Enter or = for equals, Escape or C for clear, and Backspace to delete the last digit. This makes the calculator much faster for frequent users.

What are the memory functions (M+, M-, MR, MC)?

Memory functions let you store values for multi-step calculations: M+ adds the current display value to memory, M- subtracts from memory, MR recalls (shows) the stored value, and MC clears the memory back to zero. An "M" indicator shows when memory contains a value.

Why won't the calculator work?

If the calculator isn't responding, try these steps: 1) Refresh the page using F5 or the refresh button. 2) Make sure JavaScript is enabled in your browser settings. 3) If you see "Error" in the display, press Clear (C) and try your calculation again. 4) Division by zero will show an error - this is mathematically undefined.

Related Calculators

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About This Free Full Screen Calculator

This full screen calculator is designed for users who need a simple, easy-to-use calculator with a large display. Whether you're checking your shopping receipt, helping with homework, or performing quick calculations at work, this calculator provides instant, accurate results.

Key features include:

  • Large, clear display that's easy to read on any device
  • Touch-friendly buttons for mobile and tablet users
  • Full keyboard support for desktop users
  • Memory functions for complex multi-step calculations
  • Percentage mode for common percentage operations
  • Power and root functions for more advanced calculations

Note: This calculator is intended for general arithmetic calculations. For financial calculations involving taxes, loans, or mortgages, please use our specialised calculators which include UK-specific rates and regulations.

Expert Reviewed — This calculator is reviewed by our team of financial experts and updated regularly with the latest UK tax rates and regulations. Last verified: February 2026.

Last updated: February 2026 | Verified with latest UK rates

Pro Tips for Accurate Results
  • Double-check your input values before calculating
  • Use the correct unit format (metric or imperial)
  • For complex calculations, break them into smaller steps
  • Bookmark this page for quick future access
Understanding Your Results

Our Calculator Online Free Full Screen provides:

  • Instant calculations - Results appear immediately
  • Accurate formulas - Based on official UK standards
  • Clear explanations - Understand how results are derived
  • 2025/26 updated - Using current rates and regulations
Common Questions

Is this calculator free?

Yes, all our calculators are 100% free to use with no registration required.

Are the results accurate?

Our calculators use verified formulas and are regularly updated for accuracy.

Can I use this on mobile?

Yes, all calculators are fully responsive and work on any device.

People Also Ask

Yes, our calculators use verified formulas and are regularly updated with current UK rates and regulations. Results are provided for guidance - always consult professionals for major financial decisions.

Absolutely! All our calculators are fully responsive and work perfectly on smartphones, tablets, and desktops. No app download needed.

We update all calculators with new rates as soon as they're announced - typically at the start of each tax year (April) or when significant changes occur.

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UK Calculator Editorial Team

Our calculators are maintained by qualified accountants and financial analysts. All tools use official HMRC, ONS, and NHS data. Learn more about our team.