Basic Calculator
Simple everyday calculator for quick sums, percentages and basic arithmetic.
💡 Tip: Use your keyboard number pad for faster input
How to use this calculator
This free online calculator works exactly like a pocket calculator. Click the buttons on screen, or use your keyboard for faster input, to add, subtract, multiply and divide. It handles decimals, negative numbers and percentages, making it ideal for quick everyday sums: checking a shop receipt, splitting a restaurant bill, working out a discount, or double-checking your budget figures.
Chain operations work the way you'd expect: typing 12 + 8 × 2 calculates each step as you go (12 + 8 = 20, then 20 × 2 = 40). Use AC to start again, ± to flip between positive and negative, and % to convert a number to a percentage (divide by 100).
Keyboard shortcuts
Common everyday calculations
What is 20% of £250?
Type 250 × 20, then press % → £50
Add 12.5% service charge to £84
Type 84 × 12.5, press %, then + 84 = → £94.50
Take 15% off £60
Type 60 × 15, press %, then 60 − result → £51
Split £127.40 between 4 people
Type 127.40 ÷ 4 = → £31.85
Need more advanced percentage maths, like percentage change over time or reverse percentages? Try our dedicated Percentage Calculator.
A note on order of operations
Like most simple pocket calculators, this tool calculates left to right as you enter each operation, it does not apply BODMAS/PEMDAS automatically. So 2 + 3 × 4 gives 20 (2 + 3 = 5, then 5 × 4), not 14. If you need strict mathematical order of operations, work out the multiplication or division part first, then add or subtract. For money calculations this rarely matters, but it's worth knowing when checking homework or more complex sums.
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Worked example: a £80 item with 25% off and VAT
Take 25% off £80: 80 × 0.75 = £60. If the price is then quoted before VAT, add 20%: 60 × 1.2 = £72. Doing it the other way round gives the same answer, because multiplying is order-independent: 80 × 1.2 × 0.75 = £72.
Frequently Asked Questions
Does the calculator follow the order of operations?
Enter calculations one step at a time and check each result. Many simple calculators work left to right, so 2 + 3 × 4 can return 20 instead of 14.
How do I take a percentage off a number?
Multiply by one minus the percentage. For 15% off, multiply by 0.85.
Why do I sometimes see tiny rounding differences?
Computers store decimals in binary, so a result such as 0.1 + 0.2 can show a tiny difference. Round to two decimal places for money.
Frequently Asked Questions
Is this online calculator free to use?
Yes, completely free, with no sign-up required. It works on desktop, tablet and mobile, and you can use it as many times as you like.
Does the calculator work with my keyboard?
Yes. Use the number keys, + − * / for operations, Enter or = to calculate, Backspace to delete a digit, and Escape or C to clear.
How does the % button work?
The % button divides the current number by 100. For example, to find 20% of 250, type 250 × 20 then press %, the result is 50.
Does it follow BODMAS/PEMDAS?
No, like a standard pocket calculator, it calculates left to right as you enter each operation. Work out multiplication or division steps first if you need strict mathematical order.
Can I calculate with negative numbers and decimals?
Yes. Use the ± button to switch a number between positive and negative, and the decimal point button (or . on your keyboard) for decimals.
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Not Financial Advice: This calculator is for informational and educational purposes only. Results are estimates and do not constitute financial advice, recommendations, or regulated advice. We are not authorised or regulated by the Financial Conduct Authority (FCA). Always consult a qualified financial adviser for personalised advice. Tax treatment depends on your individual circumstances and may change. Tax laws and rates may change. Past performance does not guarantee future results.
