When You Need More Than Basic Arithmetic
A scientific calculator bridges the gap between a $1 pocket calculator and a $150 graphing calculator. You get trig functions (sin, cos, tan and their inverses), logarithms (base-10 and natural), powers, roots, factorials, and constants like π and e, but without the learning curve of MATLAB or Wolfram Alpha.
The key thing most people forget: DEG vs RAD mode. If sin(90) gives you 0.894 instead of 1, you're in radian mode. Degrees divide a circle into 360 parts (intuitive for everyday angles). Radians divide it into 2π parts (required for calculus, physics, and most programming languages). One radian ≈ 57.3°. This calculator defaults to DEG because that's what most people expect, but toggle to RAD before doing any calculus-related work.
Factorials grow absurdly fast: 10! = 3,628,800 and 20! = 2.43 × 10¹⁸. Most calculators overflow at 170! (which exceeds the maximum double-precision floating point value of ~1.8 × 10³⁰⁸). This one handles up to 170! before showing Infinity.
Floating point caveat: computers represent numbers in binary, so 0.1 + 0.2 = 0.30000000000000004 in every programming language. This calculator rounds display output to 10 significant digits, but internal precision is IEEE 754 double (about 15-16 significant digits). For most practical purposes, this is more than enough.
When You'll Reach for This
Physics and engineering quick checks
Need to verify that sin(30°) × 2mg gives the right force component? Or check if ln(2)/0.05 gives the correct half-life period? This is faster than opening Python or searching for a formula. Type it in, get the answer, move on.
Trigonometry homework and exam prep
Verify your hand calculations: does arctan(1) really equal 45°? Is cos(60°) actually 0.5? When you're grinding through 20 trig problems, having a quick-check tool prevents cascading errors from one wrong step.
Financial compound growth calculations
The compound interest formula uses exponents: A = P(1 + r/n)^(nt). Plug in the numbers here to verify your spreadsheet. Also useful for Rule of 72 checks: ln(2)/r gives exact doubling time (vs the 72/r approximation).
Programming sanity checks
Before hardcoding Math.log10(1000) or Math.pow(2, 32) in your code, verify the expected output here. Especially useful for bit manipulation (2³² = 4,294,967,296, the uint32 max + 1) and logarithmic complexity estimates.
Common Mistakes and How to Avoid Them
Check DEG/RAD mode BEFORE calculating
This is the #1 source of wrong answers. sin(90) in DEG mode = 1. sin(90) in RAD mode = 0.894. If your trig result looks wrong, the mode is probably wrong. Rule of thumb: use DEG for geometry and everyday angles, RAD for calculus and physics formulas.
Factorial has a hard ceiling
170! ≈ 7.26 × 10³⁰⁶ is the largest factorial that fits in a 64-bit float. 171! = Infinity. If you need larger factorials (combinatorics, probability), use Stirling's approximation: n! ≈ √(2πn) × (n/e)ⁿ. Or use a big-number library in Python/JS.
log vs ln: know which one you need
log on this calculator means log₁₀ (common logarithm). ln means logₑ (natural logarithm). In math textbooks, "log" often means ln. In engineering and chemistry, "log" usually means log₁₀. In programming, Math.log() is always natural log. When in doubt, check: log₁₀(100) = 2, ln(e) = 1.
Don't trust the last few decimal places
IEEE 754 double precision gives ~15-16 significant digits. This calculator displays up to 10. For most purposes that's fine, but if you're doing numerical analysis where the 12th decimal place matters, use a proper CAS (Computer Algebra System) like Mathematica or SymPy.
Real Calculations
Verify a physics formula (projectile range)
Range = (v² × sin(2θ)) / g. For v=20 m/s, θ=45°, g=9.81 m/s².
Input
(20² × sin(2×45°)) / 9.81 = (400 × sin(90°)) / 9.81 = (400 × 1) / 9.81Output
40.77 meters. Steps: 20² = 400, 2×45 = 90, sin(90°) = 1, 400/9.81 = 40.77.Compound interest: exact doubling time
How long to double money at 7% annual return? Exact formula: t = ln(2) / ln(1.07).
Input
ln(2) / ln(1.07)Output
10.24 years. Compare with Rule of 72 approximation: 72/7 = 10.29 years. The approximation is off by only 0.05 years (18 days).Limitations
- Trigonometric functions use radians by default. Switch to degree mode explicitly if your input is in degrees.
- Does not support symbolic computation (algebra, calculus, equation solving). Only evaluates numeric expressions.
- Complex numbers are not supported. Square root of negative numbers will return NaN or an error.
- Precision is limited to JavaScript 64-bit floating point (~15-17 significant digits). For arbitrary precision, use dedicated math software.
Features
- Trig functions: sin, cos, tan, arcsin, arccos, arctan
- Logarithms: log₁₀ and ln (natural log)
- Powers: xʸ, x², √x, eˣ, 10ˣ
- Factorial (n!) up to 170!
- Constants: π = 3.14159265... and e = 2.71828182...
- DEG/RAD toggle (defaults to DEG)
- 100% browser-based, no server calls, no data stored
Frequently Asked Questions
Why does sin(90) give me 0.894 instead of 1?
You're in RAD mode. In radians, 90 means 90 radians (≈ 5,156°), not 90 degrees. Switch to DEG mode and sin(90) = 1. This is the most common mistake with scientific calculators. Always check the mode indicator before doing trig.
What's the largest number this calculator can handle?
About 1.8 × 10³⁰⁸ (the IEEE 754 double-precision maximum). Beyond that, it shows "Infinity." For factorials, 170! is the max (≈ 7.26 × 10³⁰⁶). For everyday calculations, you'll never hit this limit. For cryptography-scale numbers, use Python's arbitrary-precision integers.
Is log base 10 or base e on this calculator?
The "log" button is log₁₀ (common logarithm). The "ln" button is logₑ (natural logarithm). So log(1000) = 3 and ln(e) = 1. This matches most physical scientific calculators (Casio, TI). Note: in many programming languages, log() means natural log. Don't mix them up.
Can I use this for calculus?
For evaluating expressions, yes. For symbolic differentiation or integration, no. You need a CAS (Computer Algebra System) like Wolfram Alpha, Desmos, or SymPy. This calculator gives you numerical answers (e.g., the value of sin(π/4)), not symbolic ones (e.g., √2/2).
Why is 0.1 + 0.2 not exactly 0.3?
Floating-point representation. Computers store numbers in binary, and 0.1 in binary is a repeating fraction (like 1/3 in decimal). The actual result is 0.30000000000000004. This calculator rounds to 10 significant digits for display, so you'll see 0.3. But internally, the imprecision exists. This affects all calculators and programming languages. It's not a bug.
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Your Privacy
All calculations happen entirely in your browser. No data is uploaded to any server. Your mathematical expressions never leave your device.
Tips & Related Workflows
- Just need simple arithmetic? The Basic Calculator.
- Got a result you need in different units? The Unit Converter.
- Working out compound interest? There's a dedicated Interest Calculator.
- Curious about percentage changes from your results? The Percentage Calculator.