Scientific Calculator
Full scientific calculator with sin, cos, tan, log, ln, square roots, powers, memory keys and more.
By Syed Mubashir Ali · Last updated
A worked calculation, keystroke by keystroke
Say you need √(3² + 4²). Type: sqrt ( 3 ^ 2 + 4 ^ 2 ). The brackets matter: the root applies to everything inside them. Evaluate: inside the brackets, 9 + 16 = 25, and √25 = 5. The history panel shows the full expression, so if you had typed sqrt(3^2) + 4^2 by mistake, you would see 3 + 16 = 19 and know exactly what went wrong.
For trigonometry, the order is: set the mode first, then calculate. sin(30) in degrees is 0.5; in radians it is −0.988. Both are correct evaluations: of different questions. The mode indicator is small and easy to ignore, which is why it causes so many wrong answers.
Three mistakes that waste your time
First, the angle mode, covered above: check it before every trigonometric calculation, not after. Second, brackets in the wrong place. Leave one open and the calculator stops you with ‘Missing closing bracket’, but a bracket closed in the wrong spot still gives a plausible answer: (2 + 3) × 4 is 20, while 2 + (3 × 4) is 14. Check where each bracket closes when the answer surprises you.
Third, degrees and radians inside the same calculation. If one part of your working is in degrees and another in radians, no single mode is correct. Convert everything to one unit first (multiply degrees by π/180 to get radians) then calculate. Mixed units are the quietest source of wrong answers in trigonometry.
How to Use Scientific Calculator
- 1Type an expression, or build it with the buttons.
- 2Set the angle mode to degrees or radians before using any trigonometric function.
- 3Evaluate to get the result.
- 4Previous calculations appear in the history panel so you can check your working. Ans inserts the last answer into a new expression.
- 5Use the memory keys for running totals: M+ adds the expression on screen (or the last answer) to memory, M− subtracts it, MR inserts the stored value and MC clears it.
- 6Use Clear to reset the current entry.
- 7When in doubt, add brackets. They cost nothing and they remove ambiguity about the order of operations.
Frequently Asked Questions
Does the angle mode matter?
Very much. sin(30) is 0.5 in degrees and about −0.988 in radians. Check the mode indicator before any trigonometric calculation. It is the most common cause of a confidently wrong answer.
What is the history panel for?
Checking your working. A single wrong keystroke in a long calculation is invisible in the result but obvious when you can see the expression you actually entered, which is usually faster than redoing it.
How do the memory keys work?
M+ adds the current expression's value to memory (or the last answer, if the screen is empty), M− subtracts it, MR inserts the stored number into your expression and MC clears it. The stored value is shown under the keys. It's handy for adding up several separate results, such as the areas of a few rooms.
In what order are operations evaluated?
Standard precedence: brackets, then exponents, then multiplication and division, then addition and subtraction. If you are unsure how an expression will be read, add brackets. They cost nothing and remove the ambiguity.
Does anything I calculate leave my device?
No. The calculator runs entirely in your browser, so expressions and results are never sent anywhere. Nothing is stored beyond the history in the open tab, which disappears when you close it.
Can I use it in an exam?
Check your exam rules. Most exams that permit a calculator specify approved models and prohibit anything with internet access, which rules out a browser-based one regardless of what it does.
What is the difference between log and ln?
The base. log is base 10 (common logarithm) and ln is base e ≈ 2.718 (natural logarithm). log(100) = 2 because 10² = 100; ln(e) = 1. In school mathematics log usually means base 10; in calculus and beyond, log often means natural log, which is genuinely confusing. Check which one your course expects.
Why does 0.1 + 0.2 give 0.30000000000000004?
Binary floating-point arithmetic. Decimal fractions like 0.1 can't be represented exactly in binary, so the tiny representation errors accumulate. It isn't a bug in this calculator: every computer does it. For money, round to two decimals at the end rather than trusting the raw result.
How do I calculate a percentage change?
Divide the difference by the original and multiply by 100. A price rising from 80 to 100 is (100 − 80)/80 × 100 = 25%. Note the asymmetry people trip over: a 25% rise followed by a 25% fall doesn't return to the start: 100 down 25% is 75, not 80. Percentages compound against their current base.
About Scientific Calculator
The Scientific Calculator handles trigonometric, logarithmic, exponential and root functions with a switchable degree and radian mode, memory keys and an Ans key, and keeps a history of what you have evaluated. It runs entirely in your browser.
The angle mode deserves attention before every trigonometric calculation, because both modes produce a plausible number and only one is right. sin(30) is 0.5 in degrees and roughly −0.988 in radians, and nothing about the answer tells you which you asked for.
The history panel earns its place on longer work. When a result looks wrong, the fastest route to the cause is reading back the expression you actually typed rather than re-entering the whole thing: mistyped brackets in particular are invisible in a result and obvious in the expression.
Nothing you calculate leaves your device; there's no server involved and the history lives only in the open tab. If you need a calculator for an exam, check the rules first: most that allow one specify approved models and exclude anything running in a browser.
A concrete habit that saves marks: before a long calculation, estimate the answer roughly. If you are computing 47 × 32, expect something near 1500. When the calculator says 15040, you know a zero slipped in: without the estimate, 15040 looks just as plausible as 1504. The history panel then shows you exactly where the extra zero entered, which beats retyping the whole thing.