A free online scientific calculator for trig, logarithms, powers, roots, factorials and constants — with degree/radian mode and correct order of operations. No download or sign-up.
Free online scientific calculator. Supports + − × ÷, powers, roots, π, e, trigonometry (degrees or radians), logarithms, factorials and parentheses.
How the Scientific Calculator Works
This tool works like a physical scientific calculator: you build an expression by tapping number, operator and function buttons, and it evaluates the whole expression at once when you press equals. Instead of a single formula, it runs a general-purpose math engine that reads your expression, applies the correct order of operations, and resolves every function and constant you’ve inserted.
Formula: The calculator tokenizes the expression you build (numbers, + − × ÷, parentheses, and functions like sin, cos, tan, ln, log, √, x^y, x², x!, %, Ï€, e), converts it to a strict order-of-operations sequence, then evaluates it step by step — parentheses first, then functions and exponents, then × ÷, then + −. Trig functions are computed as sin(x × Ï€/180) when in DEG mode or sin(x) directly in RAD mode. “log” returns log base 10 (Math.log(x)/Math.log(10)), “ln” returns the natural log, “x!” multiplies 1×2×3×…×n for whole numbers from 0 to 170, and “%” divides the current value by 100.
- Expression — the sequence of digits, operators and parentheses you build with the button grid, shown live in the expression display above the answer
- Mode (DEG/RAD) — the toggle button that decides whether sin, cos and tan treat numbers as degrees or radians
- Function buttons — sin, cos, tan, ln, log, √, x^y, x², x!, % and the constants π and e, inserted directly into the expression at the cursor
- Ans — recalls the result of your previous calculation so you can chain it into a new expression
Example Scenarios
| Expression | Mode | Result |
|---|---|---|
| sqrt(144) | — | 12 |
| 2^10 | — | 1024 |
| sin(30) | DEG | 0.5 |
| cos(60) | DEG | 0.5 |
| 5! | — | 120 |
| log(1000) | — | 3 |
Scientific Calculator FAQ
How do I switch between degrees and radians?
Tap the mode button labeled DEG above the button grid — it toggles to RAD and back. This only changes how sin, cos and tan (and their inverses) interpret numbers; it has no effect on non-trig operations like powers or logs.What’s the difference between the log and ln buttons?
The “log” button computes the base-10 logarithm, so log(1000) gives 3. The “ln” button computes the natural logarithm, using base e, so ln of e itself gives 1. Use whichever base your problem calls for.Why does the factorial button return an error or NaN?
Factorial only works for whole numbers from 0 to 170. Entering a negative number, a decimal like 4.5, or a number above 170 produces NaN because those values are outside what a standard factorial can compute.What does the % key actually do on this calculator?
Unlike a plain “percent of” shortcut, the % key here simply divides the current value by 100 in place, converting it to its decimal equivalent — for example 50% becomes 0.5 before the rest of your expression is evaluated.How does the Ans button work?
Ans inserts the numeric result of your last completed calculation into the expression display, so you can immediately build on it — for example doubling a previous answer by typing Ans × 2 and pressing equals.What order of operations does the calculator follow?
It follows standard math convention (PEMDAS): parentheses first, then functions, powers and roots, then multiplication and division left to right, then addition and subtraction left to right — the same order you’d use solving the expression on paper.Related Calculators
Need to solve for x instead of just evaluating an expression? Try the quadratic formula calculator for equations in the form ax² + bx + c = 0, or the exponent calculator and square root calculator when you just need a quick power or root without building a full expression.