Scientific Calculator
A scientific calculator is one of those tools you need at exactly the moment you do not have one — mid-way through a physics problem, checking a compound-interest sum, or working out how many ways five cards can come out of a deck. The calculator above is free, opens instantly in your browser, and carries the full scientific keypad: trigonometry with a proper degrees-and-radians switch, logarithms, powers and roots, factorials, combinations and permutations, modulo, π and e.
It also does two things most free scientific calculators online skip. It keeps a live calculation history you can tap to reuse or edit, and it follows the correct order of operations without argument, so 12 + 8 × 5 gives 52 rather than 100.
What This Scientific Calculator Can Do
Everything sits on one screen — no menus, no second-function key to hunt for.
| Group | Keys | What they are for |
|---|---|---|
| Trigonometry | sin, cos, tan and their inverses, Deg | Rad | Angles, triangles, waves, physics |
| Logarithms | ln, log, ex, 10x, 2x | pH, decibels, growth and decay |
| Powers and roots | x2, x3, xy, √, ∛ | Areas, volumes, compound interest |
| Combinatorics | x!, nCr, nPr | Probability, lottery odds, arrangements |
| Constants and entry | π, e, EXP, Ans, |x|, 1/x, +/− | Real formulas, written the way they look |
| Everyday | + − × ÷ ( ) % mod | Ordinary arithmetic, still in BODMAS order |
Below the clock there is also a keyboard button. Switch it on and your keyboard drives the calculator directly — digits, + − * / ^ ( ) %, the decimal point, Enter for equals, Backspace to delete and Escape to switch it off again. It stays on until you turn it off, so clicking elsewhere on the page will not quietly disconnect it.
Degrees or Radians — The Setting That Causes Most Wrong Answers
If a trigonometry answer ever looks absurd, this is almost always why. In degrees, sin(30) is 0.5. In radians, sin(30) is −0.988. Both are correct; they are answers to different questions.
The Deg | Rad switch sits at the top-left of the scientific keypad and shows which one is active in blue. School geometry, surveying and most physics questions phrased in degrees want Deg. Calculus, anything with π in the angle, and programming want Rad. Check it before you trust a sine.
Two exact cases worth knowing, because they show the calculator is doing real mathematics rather than approximating: sin(180°) returns a clean 0 rather than the 1.22 × 10⁻¹⁶ that raw floating-point arithmetic produces, and tan(90°) returns "Math error" rather than an enormous meaningless number, because the tangent of a right angle genuinely does not exist.
Powers, Roots and Logarithms
The power key xy is right-associative, exactly as mathematicians write it: 2^3^2 means 2^(3^2) = 2⁹ = 512, not (2³)² = 64. The dedicated x2 and x3 keys apply to whatever you have just typed, so 7 then x2 is 49 immediately.
Roots work the same way: √ opens a bracket you fill, and ∛ handles cube roots including negative numbers — ∛(−8) is −2, which many simple calculators refuse.
For logarithms, log is base 10 and ln is base e. A base you need but do not have a key for is one division away: log₂(1024) is log(1024) ÷ log(2) = 10.
Factorials, Combinations and Permutations
These three answer counting questions, and the difference between them is simply whether order matters.
| Key | Question it answers | Example |
|---|---|---|
| x! | How many orders for all of them? | 5! = 120 |
| nCr | How many groups, order ignored? | 10 nCr 3 = 120 |
| nPr | How many arrangements, order counts? | 10 nPr 3 = 720 |
Two that show the point: a five-card poker hand is 52 nCr 5 = 2,598,960, and a six-from-49 lottery ticket is 49 nCr 6 = 13,983,816 — which is exactly how long the odds are.
Modulo, Percent and EXP
mod gives the remainder after division: 17 mod 5 = 2. It answers "what day will it be in 100 days?" — 100 mod 7 = 2, so two days on from today. Negative numbers follow the mathematical convention rather than the programming one, so −17 mod 5 = 3, never −2.
% means "divide by one hundred", so 10% is 0.10. That makes 2499 × 18% = 449.82 for GST, and 1299 × (1 − 20%) = 1039.20 for a discounted price, each in a single line.
EXP enters scientific notation: 6.02 then EXP then 23 becomes 6.02 × 10²³. It is the honest way to type Avogadro's number without counting zeros.
The History Panel
Every calculation you finish is filed in the history. Tap the expression and it loads back into the calculator so you can change one number instead of retyping the whole thing; tap the result and that value drops into whatever you are working on now. On desktop the panel opens over the calculator; on mobile it slides down as a popup.
It is session-only and lives entirely in your browser. Reload the page and it is gone. Nothing is uploaded, logged or tracked.
Worked Examples
| Problem | Type this | Answer |
|---|---|---|
| Opposite side, 30 m at 41.4° | 30 × tan(41.4) (Deg) | 26.4 |
| Hypotenuse of a 3, 5.5 triangle | √(3 x2 + 5.5 x2) | 6.26 |
| ₹10,000 at 5% for 10 years | 10000 × 1.05 xy 10 | 16,288.95 |
| log₂ of 1024 | log(1024) ÷ log(2) | 10 |
| Odds of one lottery ticket | 49 nCr 6 | 13,983,816 |
| Day of the week in 100 days | 100 mod 7 | 2 |
What It Does Not Cover
Worth saying plainly, because a tool that oversells itself wastes your time: this is not a replacement for a Casio fx-991 in every respect. There are no statistics modes, no matrices, no complex numbers and no symbolic algebra or integration. If your work needs regression, eigenvalues or an indefinite integral, a dedicated tool will serve you better.
What it does cover is the mathematics most students, teachers, engineers and analysts actually reach for in a day — trigonometry, logarithms, powers and roots, combinatorics, modulo and ordinary arithmetic in the correct order — and it covers that correctly, including the awkward corners: 2^3^2, tan(90°), negative cube roots and negative modulo. Those corners are where free calculators usually give way, which is why they are worth checking on any calculator before you rely on it.
Frequently Asked Questions
Is this scientific calculator free?
Why does sin(30) give 0.5 on one calculator and −0.988 on another?
What is the difference between log and ln?
How do I calculate nCr and nPr?
What happens with tan(90°) or division by zero?
Does it save my calculations?
Can I use my computer keyboard?
How do I enter scientific notation like 6.02 × 10²³?
Does it follow BODMAS?
Does it work on a phone?
Whatever you came here to work out, it should take a few taps and no waiting. If you only need the four operations, the basic calculator is one tab away; for writing very large or very small numbers properly there is the scientific notation calculator, and for deciding how many digits an answer deserves, the significant figures calculator. The rest are on the Monkza calculators page.
