Scientific Calculator

This calculator handles the four basic operations plus trigonometric and inverse trigonometric functions, common and natural logarithms, square roots, powers, factorials, percent, absolute value and the constants π and e, all in a single expression field. Instead of pressing one operator at a time, you write the whole expression, for example2*(3+sin(30))^2, and press Enter, so you can see the order of operations and fix mistakes before you calculate. It suits schoolwork in maths and physics, quick engineering checks, compound-growth arithmetic and verifying angle conversions. The last five calculations are listed under the keypad, and the latest result can be copied to the clipboard.

What it can do

• Trigonometry: sin, cos, tan and their inverses (the sin⁻¹, cos⁻¹ and tan⁻¹ buttons insert asin(, acos( and atan( into the field). The button at the top right switches between DEG (degrees) and RAD (radians).
• Logarithms: log is base 10 and ln is base e. The argument must be greater than 0.
• Powers and roots: the x² button, the ∛ button (which inserts ^(1/3)) and the √ button. For any other power x^y, type ^ yourself, for example 2^10.
• Other: n! (whole numbers 0 and above only), % (divides the value before it by 100), abs, π, e, parentheses and Ans for the previous result.

Order of operations and input rules

The calculator evaluates an expression in this order. Rows nearer the top bind more tightly.

Implied multiplication is not recognised, so write 2*π instead of 2π and 3*(4+1) instead of 3(4+1). A function name must be followed by a parenthesis: sin(30) works but sin30 does not. The letter e is always Euler's number (2.718…), so scientific notation such as 2e3 is not available; write 2*10^3 instead.

DEG versus RAD, with reference values

180° equals π radians, so radians = degrees × π ÷ 180. The same input sin(30) gives 0.5 in DEG mode but about −0.988 in RAD mode, which makes checking the mode the single most important habit. The table below shows common angles, calculated at build time with the same rule the calculator uses (12 significant digits, and values smaller than 1e−10 shown as 0).

Inverse functions return degrees in DEG mode and radians in RAD mode: asin(0.5) gives 30 in DEG mode and about 0.5236 in RAD mode. The domain matters too: asin and acos only accept arguments from −1 to 1.

Factorial reference

n! is the product of the whole numbers from 1 to n, and 0! is defined as 1. It grows very quickly: 20! is about 2.4 × 10¹⁸, and 170! is the largest factorial this calculator can return, because 171! exceeds the biggest number a double-precision value can hold (about 1.8 × 10³⁰⁸).

The table lists exact integers, but the calculator rounds results to 12 significant digits, so 20! appears as 2432902008180000000 rather than 2432902008176640000. For exact counts of arrangements and selections, compute with smaller numbers or use a tool built for exact integers.

Worked examples, checked by calculation

• Compound growth. $1,000 growing at 5% a year for 10 years: 1000*1.05^10 = 1628.89462678, so about $1,628.89. With monthly compounding, 1000*(1+0.05/12)^120 = 1647.00949769. The rate is an assumed figure; real accounts depend on their own terms and fees.
• Right-triangle hypotenuse. With legs of 3 and 4, sqrt(3^2+4^2) = 5.
• Recovering angles. In DEG mode asin(0.5) = 30 and atan(1) = 45.
• Logarithms. log(1000) = 3, ln(e^2) = 2 and log(2) ≈ 0.301029995664. Change of base works too: ln(8)/ln(2) = 3.
• Identity check. sin(45)^2+cos(45)^2 = 1 in DEG mode. If you get a different number, you are probably in RAD mode.
• Combinations by hand. 5!/(2!*3!) = 10, the number of ways to choose 2 items from 5.

How the expression is evaluated

The calculator does not use JavaScript's eval or a similar shortcut. It splits your text into numbers, names and operators, and then evaluates it with a small hand-written parser that only understands the functions listed above. Anything else, such as an unknown word or a stray symbol, is rejected with an error message. Everything runs locally in your browser; the expressions you type are never sent to a server.

Accuracy and limits

• Floating point. Computers store numbers as IEEE 754 double-precision values, which carry about 15 to 17 significant digits. In raw form 0.1+0.2 is 0.30000000000000004. The calculator rounds every result to 12 significant digits, so you see 0.3, and values below 1e−10 in size are shown as 0, which is why sin(180) displays 0 instead of 1.2e−16. This tidying can hide real results when you work with extremely small numbers.
• Large integers. Integers above 2⁵³ (about 9.007 × 10¹⁵) cannot all be represented exactly, and the 12-digit rounding means 2^53+1 displays as 9007199254740000. Do not use this tool for exact big-integer work.
• Undefined calculations. Division by zero, tan(90°), the square root or logarithm of a negative number (or log and ln of 0), and asin or acos of values outside −1 to 1 return an error message. Complex numbers are not supported, so (-8)^(1/3) returns "cannot be calculated" even though a real cube root of −8 exists.
• Percent. The % key simply divides the value before it by 100. 200+10% is 200.1, not 210. To add 10 percent, write 200*(1+10%) or 200*1.1.
• Tangent in RAD mode. Values such as π/2 cannot be stored exactly, so tan(π/2) returns a huge number even though the true value is undefined.
• What is not included. No graphing, matrices, calculus or statistics functions. For averages and standard deviation, use the Statistics Calculator.

Common mistakes

• Calculating a sine or cosine without checking the DEG/RAD button.
• Typing -2^2 and expecting 4. The power binds first, so the answer is −4; use (-2)^2 for 4.
• Leaving out the multiplication sign before a parenthesis or constant.
• Reading a displayed rounded result as if it were exact.

Frequently Asked Questions

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