The best free online calculator for everyday arithmetic. Fast, full-screen, browser-based — no sign-up, no download. Includes keyboard support and calculation history.
Click the result to copy it to your clipboard.
Calculators process operations in the order you enter them. For complex expressions, use the equals button after each sub-calculation to get the result before moving on.
To find 20% of 150, enter 150 × 20 % = and the calculator handles the rest. The % key divides by 100 automatically.
After pressing equals, you can continue operating on the result. Just press an operator (+ − × ÷) and the last answer becomes your starting number.
Use the +/− toggle to flip any number between positive and negative. This works mid-entry without starting over.
Double-check decimal placement in money calculations. A misplaced decimal point (e.g. 1.5 instead of 15) is the most common source of errors.
Standard calculators evaluate left to right. If your real-world problem has grouped steps (like (2+3)×4), break it into separate calculations for accuracy.
This tool covers everyday arithmetic. For academic and STEM work — scientific notation, trigonometry, calculus (integrals, derivatives), matrix operations, or 3D graphing — tools like Desmos, WolframAlpha, Symbolab, and GeoGebra are purpose-built. Our own Scientific Calculator is also in the Tools menu.
For specialist finance, dedicated tools give far more detail. A mortgage amortisation calculator shows full repayment schedules, a compound interest calculator models investment growth, and a loan repayment calculator breaks down total interest paid. We have several of these in our Finance section.
Need to convert units, work out a percentage difference, or convert a fraction to a decimal? These are common companion tasks to everyday arithmetic. Our unit converter, percentage calculator, and fraction tools are a click away in the Tools menu.
Desmos excels at graphing and high school maths. WolframAlpha handles complex symbolic maths and natural language queries. Symbolab gives step-by-step breakdowns. GeoGebra is best for visual geometry and 3D modelling. Calculator.net covers general utilities, finance, and health tools. NumWorks Online simulates a modern handheld calculator.
The best free online calculator for everyday arithmetic — fast, browser-based, and always available with no sign-up required. Supports addition, subtraction, multiplication, and division with full keyboard support and an on-screen history display.
15 + 27
Result: 42
250 × 8
Result: 2,000
144 ÷ 12
Result: 12
1,000 − 337
Result: 663
Order of operations (BODMAS / PEMDAS)
Example: 2 + 3 × 4 = 2 + 12 = 14 (not 20)
The word 'calculator' comes from the Latin 'calculus', meaning small pebble. Ancient Romans used pebbles on counting boards to perform arithmetic. The first electronic desktop calculator, the ANITA Mk 8, was released in Britain in 1961.
For everyday arithmetic, this free online calculator is fast, clean, and works instantly in your browser with no sign-up. For graphing and advanced academic maths, Desmos and WolframAlpha are widely considered the best free options.
Yes. The calculator works on any screen size, and on desktop you can use keyboard shortcuts for every operation, making it feel like a dedicated full-screen calculator app.
The expression bar above the display shows the current calculation chain. For a persistent session history, Premium members can save results to their account.
A basic online calculator covers everyday arithmetic — addition, subtraction, multiplication, division, and percentages. A scientific calculator adds trigonometry, logarithms, exponents, and factorial functions. Our Scientific Calculator tool in the Tools menu handles those advanced operations.
For step-by-step algebra and calculus (integrals and derivatives), Symbolab or WolframAlpha are the go-to choices. For graphing functions, Desmos is the most popular free online graphing calculator. For geometry and 3D modelling, GeoGebra is excellent.
It depends on the task. For mortgage amortisation, compound interest, loan repayment, and investment growth calculations, we have dedicated finance calculators in our Finance section. For more complex TVM (time value of money) problems, Calculator.net and financial-specific tools are worth exploring.