Scientific Calculator

Scientific Calculator evaluates whole expressions rather than making you press one operation at a time. Type something like sin(45) + sqrt(16) * 2 and the answer appears with the expression still visible, which means you can see what you asked for and fix a typo instead of starting again.

The function set covers what a scientific calculator is expected to have: sine, cosine and tangent with their inverses, natural and base-ten logarithms, powers and roots, exponentials, absolute value, rounding, factorials, and the constants pi and e. Degrees and radians are a switch, and the current mode is shown next to the input so you cannot forget which you are in.

Expressions are evaluated by a parser written for the job, which tokenises the input and builds a syntax tree. It never uses the JavaScript evaluator, which would run anything typed into the box as code. That matters on a public page: a calculator that evaluates arbitrary code is a security hole, not a feature.

• Full expression entry with operator precedence and brackets
• Trigonometric functions with inverses, in degrees or radians
• Natural and base-ten logarithms, powers, roots and exponentials
• Factorial, absolute value, rounding, floor and ceiling
• The constants pi and e
• Answer memory, so the previous result can be reused
• Calculation history you can click to restore
• Parsed safely, never evaluated as code

The scientific calculator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

• Working through homework that needs trigonometry
• Checking a calculation without reaching for a phone
• Evaluating a formula with several nested brackets
• Converting between degrees and radians in context
• Doing arithmetic where seeing the expression matters