Scientific Calculator
This free Scientific Calculator handles everything from everyday arithmetic to the trigonometry, logarithms and powers needed for school, college and engineering work. Alongside the standard keys it offers sin, cos and tan with a degrees or radians toggle, base ten and natural logarithms, square roots, powers and square, factorials, percentages, pi and e, and full bracket support so you can build proper expressions like 3 × (4 + 5)² and get the mathematically correct answer, with the calculator following the proper order of operations automatically.
Every expression is worked out by a safe built-in maths parser written for this page, not by handing your input to a script runner, so the calculator is both secure and predictable. Results are tidied to ten decimal places to avoid the long floating point tails that computers often produce, and clear error messages appear for genuine problems such as dividing by zero or taking the square root of a negative number, instead of a misleading answer. You can tap the buttons or simply type on your keyboard, using Enter for equals and Backspace to delete. Everything runs locally in your browser: nothing you calculate is uploaded, stored or tracked.
How to use
- Tap or type your expression using the number and operator keys.
- Use the function keys for trig, logs, roots, powers and factorials.
- Check the DEG or RAD setting before using sin, cos or tan.
- Press equals to see the result, shown above the final value.
- Press AC to clear everything, or the backspace key to delete one step.
Frequently asked questions
What is the difference between DEG and RAD?
Angles can be measured in degrees or radians, and trig functions give different answers for each. School maths usually uses degrees, while advanced maths and programming use radians. The toggle at the top switches modes, and it starts in degrees.
What does the percent key do?
It divides the number just before it by one hundred, so typing 50 % gives 0.5. In a longer expression such as 200 + 10 %, the percent applies to the 10, which makes quick discount style calculations easy to build.
Why did I get an error for a factorial?
Factorials are only defined here for whole numbers from zero upwards, and they grow extremely fast, so the calculator limits them to 170. A decimal or negative entry, or anything larger, shows an explanation instead of a wrong answer.
Can I keep calculating from a result?
Yes. After pressing equals, tapping an operator continues from the result, while tapping a number starts a fresh expression. The previous calculation stays visible above the answer until you move on.