Scientific Calculator

What is a scientific calculator?

A scientific calculator adds trigonometric functions (sin, cos, tan and their inverses), logarithms (log base 10 and natural log), powers and roots, factorials, and usually a memory function on top of basic arithmetic — the standard tool for algebra, trigonometry, and science coursework. This page works the same way online, with buttons for every function alongside a display you can also type directly into.

The main difference from a phone's basic calculator is that a scientific calculator reads a whole expression and applies the order of operations, instead of working out each step the moment you press a key. On a basic calculator, 2 + 3 × 4 often gives 20; here it gives 14, which is what your teacher and every textbook expect.

How to use this calculator

Type an expression directly into the display, or build it with the keypad — function keys like sin, log, and √ insert their opening parenthesis for you. Press 2nd to switch sin/cos/tan to their inverse (asin/acos/atan), and use the DEG/RAD toggle to control whether trig functions expect degrees or radians. Standard order of operations applies throughout, including with parentheses and exponents, so 3+4*2 correctly evaluates to 11, not 14.

A few shortcuts save keystrokes. A number written right next to a constant, function or bracket is multiplied, so 2pi, 3sin(30) and 2(3+4) work as written. After you press =, the result is stored as Ans: type Ans*2 or tap the Ans key to chain the next step without retyping. The M menu gives the classic memory keys (M+, M−, MR, MC) for a running total. Press Enter on a keyboard instead of = if you prefer typing, and use Copy link to send someone the exact expression.

Order of operations, worked through

The calculator follows the same precedence rules taught as PEMDAS (US) or BODMAS (UK): parentheses first, then exponents, then multiplication and division from left to right, then addition and subtraction from left to right. Here is how it evaluates 3 + 4 × 2 ÷ (1 − 5)^2:

1. Parentheses: 1 − 5 = −4.
2. Exponent: (−4)^2 = 16. The bracket keeps the minus sign inside the square.
3. Multiply and divide, left to right: 4 × 2 = 8, then 8 ÷ 16 = 0.5.
4. Add: 3 + 0.5 = 3.5.

Two cases trip people up. First, a leading minus applies after the power, so -3^2 is −9 while (-3)^2 is 9. Second, stacked powers work from the top down: 2^3^2 means 2^(3^2) = 2^9 = 512, not 8^2 = 64. Implied multiplication has the same rank as × and ÷ here, so 1/2(4) is read as (1/2) × 4 = 2. Some textbooks and handhelds give implied multiplication higher priority, so when an expression could be read two ways, add brackets and remove the doubt.

Degrees vs. radians

The most common wrong answer on any scientific calculator comes from the angle mode. In DEG mode, sin(30) is 0.5. Switch to RAD and the same keystrokes return −0.988031624093, because the calculator now reads 30 as 30 radians (about 1,719°). Geometry and most school trigonometry problems use degrees; calculus, physics formulas with angular speed, and anything involving π inside the angle use radians.

To convert by hand, multiply degrees by π/180 to get radians (30° × π/180 = 0.523598775598) and multiply radians by 180/π to go back. If an answer looks wildly off, check the mode before checking your algebra. One genuine edge case: tan(90°) is undefined, because cos(90°) = 0 and tan = sin ÷ cos. This calculator says "Undefined" rather than printing a huge number, which is what a calculator that rounds π would otherwise show.

Scientific notation

Press EXP after a number to insert the scientific-notation marker, then type the exponent — 6.02 EXP 23 becomes 6.02e23 (Avogadro's number). This is the calculator equivalent of the EE key on a physical scientific calculator. You can also write it out longhand with the power key, e.g. 6.02 × 10^23, which evaluates identically.

Results are shown to 12 significant digits. Anything 10¹⁵ or larger, or smaller than 10⁻⁹, switches to e-notation automatically: 2^100 displays as 1.26765060023e+30, and Planck's constant times the speed of light, 6.626e-34*3e8, displays as 1.9878e-25. Read "e+30" as "× 10³⁰". The largest factorial a standard double-precision number can hold is 170!, about 7.26e+306; 171! and beyond return an error rather than infinity.

Common functions and keys

Every example below can be typed into the display as shown. Results are from this calculator in DEG mode.

The % key only divides by 100, so 200*15% gives 30. For percentage change, percent of a total or adding tax, the percentage calculator lays out each case with labelled fields. For the mean and spread of a list of numbers, use the standard deviation calculator rather than typing the formula out term by term.

Fractions on a scientific calculator

This calculator works in decimals rather than exact fractions — divide with ÷ to get a fraction's decimal value (3 ÷ 4 = 0.75). If you need exact fraction arithmetic with simplified results and mixed numbers instead of decimals, use the dedicated fraction calculator.