Online Calculator — Free Basic & Scientific Calculator

A fast, accurate, browser-based online calculator for everyday math and advanced scientific calculations. Switch between Basic and Scientific modes, review your calculation history, and use your keyboard for instant input — all in one place.

Quick Answer: This free online calculator performs basic arithmetic (addition, subtraction, multiplication, division, percentages) and scientific functions (trigonometry, logarithms, powers, roots, factorials) directly in your browser. No installation, no signup, and your data stays on your device.

Result copied

Memory

Keyboard Shortcuts

0-9 Numbers
+ Add
- Subtract
* Multiply
/ Divide
Enter Calculate
Backspace Delete
Esc Clear all
. Decimal
( ) Parens

History

No calculations yet

1How to Use This Online Calculator

Choose a mode. Click Basic for everyday math or Scientific for trigonometry, logarithms, powers, roots, and more.
Enter your expression. Click the on-screen buttons or use your physical keyboard. The expression appears at the top of the display.
Switch angle mode if needed. In Scientific mode, toggle DEG (degrees) or RAD (radians) before using sin, cos, or tan.
Get the result. Press = or the Enter key. Your calculation is automatically saved to the History panel.
Copy or reuse. Use the Copy Result button, click a past entry in History to reuse it, or use the Memory buttons (MC, MR, M+, M−, MS) to store values.

2Features

Basic & Scientific Modes

From simple arithmetic to trigonometry, logarithms, factorials, and π/e constants — all in one tool.
Calculation History

Every calculation is saved locally. Click any entry to reuse it, or clear history with one click.
Full Keyboard Support

Type numbers, operators, and parentheses directly. Press Enter to calculate, Esc to clear.
Light & Dark Themes

A clean interface that adapts to your preference. Your theme choice is remembered on return visits.
Memory Functions

Store, recall, add to, and subtract from memory using MC, MR, M+, M−, and MS buttons.
Copy Result Instantly

One click copies the current result to your clipboard, ready to paste anywhere.

3Tips & Common Mistakes

Helpful Tips

Watch your angle mode. In Scientific mode, sin(30) returns 0.5 in DEG but −0.99 in RAD — always check DEG/RAD before trig.
Use parentheses for clarity. Even when precedence is correct, (2+3)×4 reads more cleanly than relying on implicit rules.
Percentage behavior. Pressing % after a number converts the current operand into a percentage of the previous result (e.g. 200 + 10% = 220).
Backspace ≠ Clear. Use ⌫ to remove the last character; use AC to wipe the entire expression.
Memory is persistent. Stored memory values survive page refreshes (kept in your browser's local storage).
Click history to reuse. Any past calculation can be reloaded into the display with a single click.

4Frequently Asked Questions

What is an online calculator?

An online calculator is a web-based tool that performs mathematical calculations directly in your browser, without installing any software. This calculator supports both basic arithmetic and advanced scientific functions, making it useful for students, professionals, and everyday use.

How do I use this calculator?

Click the on-screen buttons or use your keyboard to enter an expression. Switch between Basic and Scientific modes using the tabs at the top. Press = or the Enter key to evaluate. Your calculation will be saved to the History panel automatically.

Can I use this calculator on my phone?

Yes. The interface is fully responsive and touch-friendly, with large tap targets and an adaptive layout. It works smoothly on Android phones, iPhones, tablets, laptops, and desktops.

Does the calculator work offline?

Once the page has loaded, the calculator itself runs entirely in your browser using JavaScript — it does not need an internet connection for calculations. However, the page must be loaded at least once while online to function offline afterward.

What is the difference between Basic and Scientific mode?

Basic mode includes arithmetic, percentages, square root, and reciprocal functions for everyday math. Scientific mode adds trigonometry (sin, cos, tan and their inverses/hyperbolic variants), logarithms, powers, factorials, π/e constants, absolute value, and more.

What are DEG and RAD modes?

DEG (degrees) and RAD (radians) are two units for measuring angles. Most everyday users prefer DEG, while mathematicians and scientists often use RAD. Switch between them in the toolbar — your choice affects how sin, cos, and tan interpret their input.

Are my calculations stored online?

No. All calculations, history, memory, and theme preferences are stored locally in your browser using localStorage. Nothing is sent to any server, and your data never leaves your device.

Is the calculator accurate for scientific work?

Yes. The calculator uses a custom expression parser that respects standard mathematical operator precedence and double-precision arithmetic, suitable for typical scientific and engineering calculations. For ultra-high-precision or symbolic work, dedicated software is recommended.

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Developed By

Muhammad Usman

Founder, Developer & CEO

Building free, fast, and practical web tools for everyday users — from image converters to text utilities, designed to solve real problems without ads getting in your way.

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