Free Online Calculator | Basic Maths Calculator UK
Free online calculator for basic maths — add, subtract, multiply, divide. Full-screen, mobile-friendly. No download needed. Use instantly.
Last updated: February 2026
Basic Calculator
Free online basic calculator for everyday maths. Perform quick additions, subtractions, multiplications and divisions with our simple, easy-to-use calculator. Features full keyboard support, memory functions and calculation history.
Perfect for household budgeting, shopping calculations, splitting bills, or any basic arithmetic you need. Works seamlessly on desktop, tablet and mobile devices.
Calculation History
⌨ Keyboard Shortcuts
How to Use This Basic Calculator
Our basic calculator is designed for simplicity and ease of use. Here's how to get the most out of it:
Basic Operations
- Addition (+): Click a number, then +, then another number, then =
- Subtraction (−): Click a number, then −, then the number to subtract, then =
- Multiplication (×): Click a number, then ×, then the multiplier, then =
- Division (÷): Click a number, then ÷, then the divisor, then =
- Percentage (%): Calculate percentages of numbers (e.g., 150 × 20% = 30)
Using Memory Functions
Memory functions are useful for multi-step calculations:
- M+ (Memory Add): Adds the current displayed number to memory
- M− (Memory Subtract): Subtracts the current displayed number from memory
- MR (Memory Recall): Displays the number stored in memory
- MC (Memory Clear): Clears the memory (sets it to zero)
Understanding BODMAS (Order of Operations)
In the UK, we use BODMAS to remember the order in which mathematical operations should be performed:
| Letter | Stands For | Example |
|---|---|---|
| B | Brackets | (3 + 2) × 4 = 20 |
| O | Orders (powers/roots) | 3² + 4 = 13 |
| D | Division | 12 ÷ 4 + 2 = 5 |
| M | Multiplication | 3 × 4 + 2 = 14 |
| A | Addition | 5 + 3 - 2 = 6 |
| S | Subtraction | 10 - 4 + 2 = 8 |
Note: This basic calculator performs operations sequentially. For complex expressions requiring BODMAS order, consider our Scientific Calculator.
Common UK Calculations
Here are some everyday calculations this calculator helps with:
| Scenario | Calculation | Example |
|---|---|---|
| Splitting a bill | Total ÷ Number of people | £84 ÷ 4 = £21 each |
| Adding VAT (20%) | Price × 1.2 | £100 × 1.2 = £120 |
| Removing VAT | Price ÷ 1.2 | £120 ÷ 1.2 = £100 |
| Tip (10%) | Bill × 0.1 | £65 × 0.1 = £6.50 |
| Service charge (12.5%) | Bill × 0.125 | £80 × 0.125 = £10 |
| Discount (25% off) | Price × 0.75 | £40 × 0.75 = £30 |
| Miles to km | Miles × 1.609 | 50 × 1.609 = 80.45 km |
| Km to miles | Km × 0.621 | 100 × 0.621 = 62.1 miles |
Multiplication Tables Reference
A quick reference for times tables frequently used in mental maths:
| × | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|
| 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 |
| 3 | 6 | 9 | 12 | 15 | 18 | 21 | 24 | 27 | 30 |
| 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 | 36 | 40 |
| 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 |
| 6 | 12 | 18 | 24 | 30 | 36 | 42 | 48 | 54 | 60 |
| 7 | 14 | 21 | 28 | 35 | 42 | 49 | 56 | 63 | 70 |
| 8 | 16 | 24 | 32 | 40 | 48 | 56 | 64 | 72 | 80 |
| 9 | 18 | 27 | 36 | 45 | 54 | 63 | 72 | 81 | 90 |
| 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
Percentage Calculations Guide
Percentages are among the most common calculations in everyday life, yet they frequently cause confusion. Here is a clear guide to the most useful percentage operations you can perform with this calculator.
Finding a Percentage of a Number
To find X% of a number, multiply the number by X divided by 100. For example, to find 15% of £240, calculate 240 x 0.15 = £36. This is useful for working out tips, discounts, tax amounts, and interest payments.
Adding a Percentage to a Number
To add VAT or any percentage markup, multiply by (1 + percentage/100). For 20% VAT on £85, enter 85 x 1.2 = £102. For a 5% service charge on £64, enter 64 x 1.05 = £67.20.
Removing a Percentage from a Number
To find the pre-VAT price of an item that includes 20% VAT, divide by 1.2. For instance, if a product costs £120 including VAT, the net price is 120 / 1.2 = £100. This is a common source of error -- many people incorrectly subtract 20% of the VAT-inclusive price, which gives the wrong answer.
Finding What Percentage One Number Is of Another
Divide the part by the whole and multiply by 100. If you scored 37 out of 50 on a test, calculate 37 / 50 x 100 = 74%.
Common Percentage Mistake to Avoid
A frequent error is assuming that adding and then removing the same percentage returns you to the original number. It does not. If a price increases by 10% from £100 to £110, a subsequent 10% decrease gives £110 x 0.9 = £99 -- not £100. The percentages are calculated on different base amounts.
When to Use a Basic Calculator vs a Scientific Calculator
Knowing which calculator tool to reach for saves time and prevents errors. Here is a practical comparison to help you choose the right tool for the task.
| Task | Basic Calculator | Scientific Calculator |
|---|---|---|
| Shopping totals and bill splitting | Best choice | Unnecessary complexity |
| VAT and percentage calculations | Best choice | Also works |
| Household budgeting | Best choice | Also works |
| Trigonometry (sin, cos, tan) | Not supported | Required |
| Powers and square roots | Not supported | Required |
| Complex BODMAS expressions | Sequential only | Required |
| Logarithms and exponentials | Not supported | Required |
| GCSE/A-Level maths homework | Basic questions only | Required for most tasks |
For most adults handling day-to-day finances -- working out change, calculating tips, splitting restaurant bills, or checking utility costs -- a basic calculator is the ideal tool. It is faster to use, has fewer buttons to navigate, and reduces the chance of accidentally pressing an advanced function key. Reserve the scientific calculator for maths coursework, engineering tasks, or any calculation involving exponents, roots, or trigonometric functions.
Frequently Asked Questions
You can use your keyboard to enter numbers (0-9), operators (+, -, *, /), decimal point (.), press Enter or = to calculate, Escape to clear all, and Backspace to clear the current entry. This makes calculations much faster than clicking buttons. The keyboard shortcuts work automatically when the page is loaded.
BODMAS stands for Brackets, Orders, Division, Multiplication, Addition, Subtraction. It's the standard order of operations used in the UK education system. It ensures everyone calculates mathematical expressions in the same order, preventing ambiguity. For example, 2 + 3 × 4 equals 14 (not 20) because multiplication comes before addition.
M+ adds the current display value to memory, M− subtracts it from memory, MR recalls the stored memory value to the display, and MC clears the memory. These are incredibly useful for multi-step calculations. For example, when adding up a shopping list, press M+ after entering each item's price, then MR to see the total.
Yes, this calculator is fully responsive and works on all devices including smartphones, tablets, laptops and desktop computers. The button sizes are optimised for touch screens on mobile devices, making it easy to tap numbers and operators accurately. The calculation history panel adapts to smaller screens automatically.
To find a percentage of a number, multiply by the percentage as a decimal. For example, to find 20% of 150: enter 150, press ×, enter 0.2, press =. The result is 30. To add a percentage (like VAT), multiply by 1 plus the percentage: 100 × 1.2 = 120 (100 plus 20%).
C (Clear) completely resets the calculator, clearing the current number, the expression, and starting fresh. CE (Clear Entry) only clears the current number you're entering but keeps any previous calculation in progress. Use CE if you've made a typo in the current number but want to continue your calculation.
This calculator uses JavaScript's built-in mathematical operations, providing accuracy to approximately 15-17 significant figures (standard IEEE 754 double precision). Results are automatically rounded to 10 decimal places to avoid floating-point display issues. For most everyday calculations, this level of precision is more than sufficient.
The calculation history is stored locally in your browser during your current session. You can click on any previous calculation to reload that result into the calculator. The history is cleared when you close the browser tab or click the "Clear History" button. Your calculation history is never sent to any server — it stays completely private on your device.
Related Calculators
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 Basic Calculator 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
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