Trigonometry, logarithms, powers, roots, factorials and percentages — with correct order of operations, degrees or radians, memory, a saved history, and full keyboard entry. Free, instant, and works in light or dark mode.
sin · cos · tan ln · log · eˣ xʸ · √ · n! Memory & history
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DEG
How to use the scientific calculator
Enter an expression. Tap the keypad or click the calculator and type with your keyboard — digits 0–9, + − * / ^, parentheses, % and !. The result previews live as you type; press = or Enter to lock it in.
Switch to the Scientific keypad for functions. Use the Scientific tab for sin, cos, tan, ln, log, powers (xʸ and x²), roots (√), reciprocals (1/x) and factorials (n!). Tap 2nd to reach inverse functions such as sin⁻¹, eˣ and 10ˣ.
Choose degrees or radians. Trigonometry uses degrees by default. Switch to RAD for radian input; the unit badge above the result shows which is active so you never mix them up by accident.
Use memory and history. M+ adds the shown value to memory and MR recalls it; MC clears it. Every result is saved to History on this device — tap an entry to reuse its expression, and Copy puts the answer on your clipboard.
Worked examples
Each of these evaluates live in the calculator above — tap an example chip to load it. They show how the engine treats angles, logarithms, powers, factorials, percentages, and implicit multiplication.
Expression
Result
What it shows
sin(30)
0.5
Trigonometry in degrees — the sine of a 30° angle. Switch to RAD and you would type sin(π/6).
log(1000)
3
The base-10 logarithm: 10³ = 1000. Use ln for the natural (base-e) logarithm.
2^10
1024
A power: two to the tenth. The xʸ key inserts ^; x² is a one-tap shortcut for squaring.
√(144)
12
A square root. The √ key opens a bracket so the whole group under the root is clear.
5!
120
A factorial: 5 × 4 × 3 × 2 × 1. Defined only for whole numbers from 0 upward.
200 + 10%
220
Contextual percent — 10% of 200 is added. On its own, 10% would simply be 0.1.
2(3 + 1)
8
Implicit multiplication and parentheses: the bracket is evaluated first, then multiplied by 2.
ln(e)
1
The natural logarithm of Euler’s number e is exactly 1, by definition.
Functions & order of operations
Order of operations (PEMDAS)
The calculator evaluates parentheses first, then exponents, then multiplication and division (left to right), then addition and subtraction. Exponents are right-associative, so 2^3^2 = 2^(3^2) = 512. A leading minus binds looser than a power, so −3² = −9, while a minus inside the exponent works as expected: 2^−3 = 0.125. Writing a number next to a bracket, constant, or function multiplies them — 2(3+1), 2π, and 3sin(30) all evaluate correctly.
Degrees vs radians
Degrees split a circle into 360 parts; radians use the arc length of a unit circle, so a full circle is 2π. Use DEG for everyday geometry and RAD for calculus and physics. The active unit is shown next to every result, and inverse trig functions return their answer in the same unit.
ln vs log
ln is the logarithm to base e (≈ 2.71828) and log is the logarithm to base 10; log2 is available for base 2. Logarithms are defined only for values greater than zero.
Factorials
The factorial n! multiplies every whole number from 1 to n, so 5! = 120. It is defined only for whole numbers of zero or more (0! = 1); decimals or negatives return a short message rather than a guess.
How percentages are interpreted
A standalone percentage is just a fraction: 50% = 0.5. In addition and subtraction it becomes a percentage of the left-hand value — 200 + 10% = 220 and 200 − 10% = 180 — which matches how shops and most pocket calculators apply discounts and markups. With × or ÷ it stays a plain fraction.
Frequently asked questions
How does the calculator decide the order of operations?
It follows standard mathematical precedence (PEMDAS/BODMAS): parentheses first, then exponents, then multiplication and division, then addition and subtraction. Exponents are right-associative, so 2^3^2 means 2^(3^2). A leading minus is looser than a power, so −3² = −(3²) = −9, while 2^−3 = 0.125. Implicit multiplication is supported: 2π, 2(3+1), and 3sin(30) all work.
What is the difference between DEG and RAD?
It sets the unit for trigonometry. In DEG (the default) a full circle is 360°, so sin(30) = 0.5. In RAD a full circle is 2π, so you would enter sin(π/6) for the same result. The badge above the result always shows which unit is active, and inverse functions (sin⁻¹, cos⁻¹, tan⁻¹) return their answer in the same unit.
What is the difference between ln and log?
ln is the natural logarithm (base e ≈ 2.71828); log is the common logarithm (base 10). So ln(e) = 1 and log(1000) = 3. Use log2 for base-2 logarithms. All of them require a value greater than zero.
How does the percent (%) key work?
On its own, x% means x ÷ 100, so 50% = 0.5. In addition and subtraction it is contextual: 200 + 10% adds 10% of 200 to give 220, and 200 − 10% gives 180. With multiplication or division it stays as a plain fraction, so 5 × 10% = 0.5. This matches how most everyday and desktop calculators treat percentages.
Why does tan(90°) show “undefined”?
The tangent of 90° (and 270°, etc.) is undefined — its graph has a vertical asymptote there. Because 90° is not exactly representable in binary, a naïve calculation would return a huge but finite number that misrepresents the truth, so the calculator reports it as undefined instead. The same applies to √ of a negative number, ln of zero, and dividing by zero, which all return a short, plain-language message rather than a wrong value.
Does it remember my calculations?
Yes. Every result is saved to a History list stored only in your own browser on this device (in localStorage) — nothing is uploaded. Tap any entry to reuse its expression, or use Clear to empty the list. Your angle, decimal, and separator settings are remembered the same way.
How precise are the results?
Calculations use IEEE-754 double precision (about 15–17 significant digits). For display, “Auto” shows up to 12 significant figures and quietly absorbs tiny rounding artefacts (so cos(90°) reads 0, not 6×10⁻¹⁷); you can also fix the result to 2, 4, 6, or 8 decimals. Numbers that are very large or very small are shown in ×10ⁿ scientific notation.
Precision & limitations. Calculations use IEEE-754 double precision (about 15–17 significant digits). The “Auto” display shows up to 12 significant figures and absorbs sub-10⁻¹³ rounding artefacts so identities like cos(90°) read 0; very large or very small numbers use ×10ⁿ notation. This is a general-purpose educational tool — verify results that inform important academic, financial, or engineering decisions.
Last reviewed: 15 June 2026. Formula and assumptions reviewed for accuracy.
Note
Results are computed in your browser and rounded for display. For high-stakes work, double-check critical figures.
Built by Calculator Matters · Last reviewed 15 June 2026 · [email protected]
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