Scientific Calculator
Type an expression or use the keypad — the result updates live, and pressing = saves it to the history below.
All calculations run locally in your browser. Press Enter or = to save to the history.
How it works
- Type an expression such as 2×sin(30)+√9, or tap the keypad keys, including π, e, powers, and parentheses.
- Pick Deg or Rad before using trig functions, and use the Inv key to switch sin, cos, and tan to their inverses.
- Press = or Enter to save the calculation to the history; tap any history entry to load it again, and use ANS to reuse the last result.
Frequently asked questions
- How does the calculator evaluate expressions without a server?
- The page contains a small math engine written in JavaScript that tokenizes your expression and evaluates it with the standard shunting-yard algorithm, respecting parentheses and operator precedence. Everything runs locally in your browser, so results appear instantly as you type and nothing is sent anywhere.
- What is the difference between degree and radian mode?
- Trigonometric functions interpret their input differently depending on the mode: sin(90) is 1 in degree mode but about 0.894 in radian mode, where the input is read as 90 radians. Degree mode suits everyday geometry problems, while radian mode is standard in calculus and physics. The toggle also converts the output of the inverse functions sin⁻¹, cos⁻¹, and tan⁻¹.
- How accurate are the results?
- Calculations use IEEE 754 double-precision floating point, the same format used by graphing calculators and spreadsheets, giving about 15 significant digits. Results are displayed rounded to 12 significant digits, which hides tiny binary rounding artifacts such as 0.1 + 0.2 showing as 0.30000000000000004.
- What does the ANS key do and how does the history work?
- ANS inserts the result of your last completed calculation, so you can chain steps like ANS×2 without retyping numbers. Every time you press = the expression and its result are added to the history list, and clicking an entry loads that expression back into the input. The history lives only in the page and clears when you close the tab.
- Why does the calculator show an error instead of a result?
- An error message appears when the expression cannot be evaluated yet — for example an operator with a missing operand, an unmatched closing parenthesis, division by zero, or a domain problem like the square root of a negative number. The message names the specific issue, so fixing the expression is usually a matter of reading it. Unclosed opening parentheses are forgiven and closed automatically.
About this tool
This free scientific calculator handles the full set of operations found on a physical handheld: the four basic operators, powers and roots, natural and base-10 logarithms, the constants π and e, percentages, and trigonometric functions with their inverses in either degree or radian mode. You can type expressions directly with a keyboard — including parentheses and nested functions like ln(√(2)+1) — or build them with the on-screen keypad, which is sized for comfortable use on a phone.
Under the hood the calculator does not rely on any server or on JavaScript’s eval. Your expression is broken into tokens, converted to postfix form with the shunting-yard algorithm, and evaluated step by step, which is how compilers and serious calculator apps do it. That means operator precedence, right-associative exponentiation, unary minus, and implicit multiplication such as 2π or 3(4+5) all behave the way a math textbook expects. Because the entire engine runs client-side, nothing you calculate ever leaves your device, and the page keeps working offline once loaded.
The live result updates on every keystroke, so you can watch a long expression take shape and catch mistakes early. Pressing = commits the calculation to a history list; tapping an entry restores it for editing, and the ANS key carries the previous result into the next expression — handy for iterative work like compound interest steps, unit conversions, or checking homework line by line.
A few practical tips: switch to degree mode before geometry or navigation problems and back to radians for calculus; use the x² and xʸ keys for powers rather than repeated multiplication; and remember that log is base 10 while ln is base e. If an expression ends with several open parentheses, you can simply press = — the calculator closes them for you.