This free online scientific calculator handles everything a handheld scientific calculator does — trigonometry, logarithms, exponents, roots, factorials, and the constants π and e — right in your browser with no download or sign-up. It follows the full mathematical order of operations, so multi-step expressions evaluate exactly as they would on paper.
Use it for algebra and geometry homework, chemistry and physics problem sets, statistics coursework, or any quick calculation beyond a basic four-function calculator. Trigonometric functions work in degrees, matching how most classroom problems are stated, and every calculation happens instantly on your own device.
Supported Functions
The calculator covers the standard scientific function set:
- Trigonometry: sin, cos, tan and their inverses, evaluated in degrees — sin(30) = 0.5, tan(45) = 1
- Logarithms: log for base 10 and ln for the natural log (base e) — log(1000) = 3, ln(e) = 1
- Powers and roots: squares, arbitrary powers (x^y), square roots — 2^10 = 1,024, √144 = 12
- Factorial: n! multiplies every whole number up to n — 6! = 720; factorials grow explosively (20! exceeds 2.4 quintillion)
- Constants: π ≈ 3.14159265 and e ≈ 2.71828183, accurate to full floating-point precision
- Parentheses for grouping, plus percent and sign change
Because trig here works in degrees, remember to convert if a textbook problem gives angles in radians: multiply radians by 180/π.
Order of Operations (PEMDAS)
The calculator applies the standard order of operations rather than evaluating strictly left to right:
- P — Parentheses first: innermost groups before anything else
- E — Exponents and roots, including functions like sin and log
- MD — Multiplication and Division, left to right, equal priority
- AS — Addition and Subtraction, left to right, equal priority
So 2 + 3 × 4 evaluates to 14, not 20, because multiplication binds before addition. This is where cheap four-function calculators silently give wrong answers — they compute left to right and return 20.
When in doubt, add parentheses: (2 + 3) × 4 forces 20 explicitly. Common trap: −3² means −(3²) = −9 under standard convention, while (−3)² = 9. Parentheses make your intent unambiguous every time.
Common Student Use Cases
Typical problems this calculator handles in one expression:
- Right-triangle trigonometry: a ladder leaning at 70° reaching a wall — height = 20 × sin(70) ≈ 18.79 ft
- Compound growth: $500 at 4% for 10 years — 500 × 1.04^10 ≈ $740.12
- pH from concentration in chemistry: pH = −log(0.00035) ≈ 3.46
- Exponential decay with e: remaining amount = 100 × e^(−0.3 × 5) ≈ 22.31
- Combinatorics: ways to arrange 8 books on a shelf = 8! = 40,320
- Distance formula: √((7−2)² + (9−3)²) = √61 ≈ 7.81
Exam tip: many standardized tests (SAT, ACT, AP) allow scientific calculators, so practicing the same keystrokes here transfers directly. For multi-step problems, keep intermediate results at full precision and round only the final answer.
Frequently Asked Questions
Does this calculator use degrees or radians?
Trigonometric functions evaluate in degrees, which matches how most school and everyday problems are stated — sin(30) returns 0.5. If your problem gives an angle in radians, convert first by multiplying by 180/π; for example, π/6 radians × 180/π = 30 degrees.
What is the difference between log and ln?
log is the base-10 logarithm: log(1000) = 3 because 10³ = 1000. ln is the natural logarithm with base e ≈ 2.718: ln(e²) = 2. Base 10 dominates chemistry (pH) and decibel scales, while base e appears in calculus, continuous growth, and decay problems. They differ by a constant factor: ln(x) = log(x) × 2.3026.
Why does 2 + 3 × 4 equal 14 and not 20?
Because of the order of operations (PEMDAS): multiplication is performed before addition, so 3 × 4 = 12 is computed first, then 2 + 12 = 14. A calculator that answers 20 is evaluating left to right, which is mathematically incorrect. To force addition first, write (2 + 3) × 4.
What is a factorial and what is it used for?
The factorial n! is the product of all whole numbers from 1 to n: 5! = 5 × 4 × 3 × 2 × 1 = 120. It counts arrangements — 5 people can line up in 120 different orders — and underpins permutations, combinations, and probability. Factorials grow extremely fast: 15! already exceeds 1.3 trillion. By convention, 0! = 1.
Is this online scientific calculator free to use?
Yes — completely free with no download, registration, or usage limits. It runs entirely in your web browser on any device, including phones and tablets, so it works anywhere you have the page loaded. All calculations are performed locally on your device rather than on a server.