Calculator
Simple and reliable online calculator
How to use Calculator
Simple and reliable online calculator with basic arithmetic operations. Works on mobile and desktop. Free, no signup required.
When do you need an online calculator?
A browser-based calculator is immediately available on any device without unlocking your phone or finding a physical calculator. It is the fastest option for quick arithmetic during work, study, or everyday tasks.
- Invoicing and billing: Quickly calculate totals, apply discounts, or check that figures add up before sending an invoice.
- Shopping: Calculate unit prices, compare deals, or check if a bulk purchase saves money.
- Cooking: Scale recipe quantities — multiply ingredients for more servings or divide for fewer.
- Splitting costs: Divide a bill, calculate each person's share, or work out a fair split for shared expenses.
- Checking mental arithmetic: Verify a quick mental calculation before committing to a decision.
Order of operations: This calculator follows standard mathematical precedence (PEMDAS/BODMAS) — multiplication and division are evaluated before addition and subtraction. Use parentheses to control the order: (2 + 3) × 4 = 20, not 2 + 3 × 4 = 14.
Frequently Asked Questions
What is the order of operations?
PEMDAS (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction) — also called BODMAS or BIDMAS. Multiplication and division are evaluated left-to-right before addition and subtraction. Always use parentheses when in doubt: (2+3)×4 gives 20, while 2+3×4 gives 14.
How do I calculate a percentage of a number?
Multiply the number by the percentage divided by 100. For example, 15% of 80 = 80 × 0.15 = 12. Alternatively, use the dedicated Percentage Calculator tool for more complex percentage operations.
What is the difference between / and ÷?
They mean the same thing — division. The ÷ symbol is traditional; / is the standard in computing and programming. This calculator accepts both.
How do I calculate square roots?
Use the √ button or type sqrt(). For example, √144 = 12. For the scientific calculator with more advanced functions including cube roots, logarithms and trigonometry, use the Scientific Calculator tool.
Can I use the keyboard with this calculator?
Yes — type numbers and operators directly from your keyboard. Enter or = submits the calculation. Backspace deletes the last character. This is faster than clicking buttons for longer calculations.
Basic calculator vs scientific calculator vs spreadsheet
A basic calculator handles arithmetic — addition, subtraction, multiplication, division, and percentages. A scientific calculator adds trigonometry, logarithms, exponents, and constants (π, e) — needed for engineering and science. A spreadsheet (Excel, Google Sheets) is best for calculations involving large datasets, formulas across cells, or repeated calculations. For quick one-off arithmetic, a basic calculator is the fastest tool.