Calculator
No calculations yet
Free Online Calculator – Simple & Scientific Calculator
Use this calculator for an arithmetic expression or for a scientific function that is awkward to work through by hand. Simple mode handles the four operations, decimals, percentages, and negative values. Scientific mode adds trigonometric functions, logarithms, roots, powers, factorials, absolute value, and the constants π and e.
The display keeps the current expression separate from its result, and the history lists recent calculations for reference. This is useful when checking a sequence of measurements, revisiting an earlier total, or comparing several values without re-entering each one.
The calculator is part of our guide to VioApps math tools, which explains when to use it versus the equation solver, unit converter, or graphing calculator.
What Is an Online Calculator?
This page evaluates the expression you enter and returns a numerical result. It is not a symbolic equation solver: use the Equation Solver when you need to solve for an unknown or simplify an algebraic expression. Before using a result in coursework or a consequential calculation, check that the expression, units, and rounding match the question you are answering.
Basic Arithmetic
Addition, subtraction, multiplication, division, percentages, and decimal calculations for everyday tasks.
Scientific Functions
Trigonometry (sin, cos, tan), logarithms (log, ln), square roots, exponents, and factorials.
Mathematical Constants
Built-in constants including π (Pi) for geometry and e (Euler's Number) for exponential calculations.
Calculation History
Track recent calculations and easily reference or reuse previous results.
Angles in Degrees
Trigonometric functions treat the input as degrees, not radians, so sin(30) returns 0.5 and tan(45) returns 1.
Large or Tiny Results
Very large or very small results switch to exponential form, such as 1.2e+16, so long numbers stay readable.
How to Use the Online Calculator
- Choose Simple Mode for basic arithmetic or Scientific Mode for advanced calculations.
- Enter numbers using the on-screen keypad or keyboard.
- Select the desired mathematical operation.
- Press the equals (=) button to calculate the result.
- Review previous calculations in the history panel.
Keyboard Shortcuts
- 0-9 - Enter numbers
- + - * / - Operators
- Enter - Calculate result
- Escape - Clear all
- Backspace - Delete last character
Common Use Cases
- Checking the total cost of several items before a purchase
- Calculating a right-triangle side with square roots and powers
- Comparing repeated measurements while keeping intermediate results visible
- Evaluating a trigonometric or logarithmic expression from a formula
Good to Know When Reading a Result
- Trig uses degrees. sin, cos, and tan expect degrees, so cos(60) returns 0.5.
- log is base 10, ln is base e. Use log for powers of ten and ln for natural logarithms.
- Factorials are for whole numbers and grow extremely fast, so large inputs lose precision.
- Dividing by zero shows an error rather than a number, because the result is undefined.
- History is stored in your browser and stays until you clear it, so avoid a shared device for sensitive figures.
- Need to solve for an unknown or simplify algebra? Use the Equation Solver instead.
About VioApps
This calculator is part of VioApps, a browser-based collection of everyday utility tools. We built the calculator to make basic arithmetic and scientific math accessible without ads-heavy interstitials, popups, or installs. Every calculation runs locally in your browser so your inputs never leave your device.
Fast & Light
No downloads required
Secure
Your data stays private
Responsive
Works on all devices