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Scientific Calculator — Trig, Logs, Powers & More in Your Browser

A full scientific calculator that handles trigonometry, logarithms, exponents, factorials, and constants — without installing anything. Supports DEG/RAD toggle, operator chaining, and the functions you actually need for physics homework, engineering estimates, or quick sanity checks. Runs client-side, no data leaves your browser.

DEG Mode
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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

1.

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.

2.

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.

3.

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.

4.

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) / 9.81

Output

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).

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
  • Runs 100% in browser, 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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