Scientific Calculator
Evaluate arithmetic and functions like sin, cos, log and sqrt safely. Supports parentheses and powers.
Formula last reviewed 15 September 2026 · How we verify our calculators
Result
14
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Frequently asked questions
Arithmetic (+, −, ×, ÷), powers (^), parentheses, the constants pi and e, and functions sin, cos, tan, sqrt, log (base 10), ln and abs.
Yes. It follows standard precedence — powers, then multiplication and division, then addition and subtraction — with parentheses overriding the rest. So 2 + 3 × 4 = 14.
Radians. To use degrees, convert first by multiplying by pi/180, for example sin(30 * pi / 180).
Yes. It uses a purpose-built parser, never JavaScript’s eval, so it cannot run arbitrary code. Anything that is not valid maths is rejected with an error.
Why 2 + 3 × 4 is 14
The expression **2 + 3 * 4 evaluates to 14**, not 20.
Multiplication binds more tightly than addition, so 3 × 4 is computed first and then added to 2. A calculator that returned 20 would be evaluating strictly left to right, which is what simple four-function calculators do and what expression parsers deliberately do not.
Order of operations
The standard precedence, from highest to lowest:
1. Parentheses — anything grouped is evaluated first 2. Exponents — powers and roots 3. Multiplication and division — equal precedence, evaluated left to right 4. Addition and subtraction — equal precedence, evaluated left to right
Two details within that cause most disagreements:
Multiplication and division share a level. In 8 ÷ 4 × 2, division comes first because it appears first: (8 ÷ 4) × 2 = 4. Reading it as 8 ÷ (4 × 2) = 1 is wrong.
Exponentiation associates right to left. 2^3^2 is 2^(3^2) = 2^9 = 512, not (2^3)^2 = 64.
When in doubt, use parentheses. An expression that needs a precedence rule explained is an expression that should have been bracketed.
Functions available
Beyond the four operations, a scientific calculator typically provides:
Trigonometric — sin, cos, tan and their inverses. Critically, these expect an angle unit, and whether the calculator is in degrees or radians changes every answer. sin(90) is 1 in degrees and about 0.894 in radians. Most programming languages and many calculators default to radians; most school problems are stated in degrees.
Logarithmic — log (base 10) and ln (natural, base e). Note that in most programming contexts `log` means the natural logarithm, which is the reverse of the calculator convention and a routine source of error when moving between the two.
Exponential and roots — powers, square root, nth root.
Constants — π ≈ 3.14159, e ≈ 2.71828.
Floating point, and why 0.1 + 0.2 is not 0.3
Calculators and computers store decimals in binary floating point, and most decimal fractions have no exact binary representation — just as 1/3 has no exact decimal representation.
The consequence is that 0.1 + 0.2 evaluates to 0.30000000000000004 rather than 0.3, and comparisons like `0.1 + 0.2 == 0.3` return false. Results are typically rounded for display, which hides the effect until it matters.
Two practical implications: never compare floating-point results for exact equality — compare whether the difference is below a small tolerance; and for money, work in the smallest unit (paise) as integers rather than in rupees as decimals.
Errors also accumulate across long chains of operations, so a sequence of calculations can drift measurably from the exact answer.
Reading the result
For very large or very small values, results appear in scientific notation — 1.5e8 means 1.5 × 10⁸, or 150,000,000. The `e` here denotes the exponent, not Euler's number.
Some expressions are genuinely undefined rather than merely difficult: division by zero, the logarithm of a non-positive number, and the square root of a negative number in real arithmetic. A calculator returning an error for these is correct.
Common mistakes
Assuming left-to-right evaluation. Precedence rules apply.
Mixing degrees and radians. The most frequent trigonometry error by a wide margin.
Confusing log and ln. Conventions differ between calculators and programming languages.
Comparing floats for exact equality. Use a tolerance.
Omitting parentheses on ambiguous expressions. If it needs explaining, bracket it.