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Yes. On a computer, type digits and + - * / ^ ( ) % ! directly, then press Enter or = for the result. * / - show up as × ÷ −. The on-page keys insert at the cursor; CE deletes the character before the cursor, and a function name is deleted whole. Once a result is shown, the key turns into AC, and one click clears everything. On a phone, use the on-page keys: the system keyboard does not open, and you can long-press the expression box to paste.

A percentage right after + or − is a percentage of the number before it: 200+10% is 200 plus 10% of 200, which is 220, and 200−10% is 180. In every other case, % simply divides by 100: 50% is 0.5, 200×10% is 20, and (100+10)% is 1.1.

Parentheses first, then factorial, percent and squaring, then powers, then the minus sign, then multiplication and division, and addition and subtraction last. Powers go from right to left: 2^3^2 is 2 to the power 9, which is 512. −3^2 squares 3 first and then negates it, giving −9; to square −3, write (−3)^2. A multiplication sign is added automatically when a number, π, a parenthesis or a function are written side by side, as in 2π, 2(3+4) or 3sin(30). The added sign has the same rank as × and goes left to right, so 1÷2π is π÷2; to divide by 2π, add parentheses. Closing parentheses missing at the end are added for you.

Deg means degrees and Rad means radians; the default is Deg. In Deg, sin(30) is 0.5; switch to Rad and 30 is read as radians, so sin(30) is about −0.988. The setting only affects the input of sin, cos and tan and the results of sin⁻¹, cos⁻¹ and tan⁻¹. When the angle is a whole multiple of 90°, the result is exactly 0, 1 or −1. tan 90° is undefined and shows "Domain error".

Inv switches the function keys to their inverses: sin⁻¹, cos⁻¹, tan⁻¹, eˣ, 10ˣ and x². They switch back by themselves after you press one function key. EXP enters scientific notation: 3 EXP 5 is 3E5, which is 300000. Scientific notation needs an uppercase E; a lowercase e is Euler's number, 2.718…, so 2e means 2 times e. Ans is the result of the last = press. Once a result is shown, pressing an operator key such as + − × ÷ continues from Ans, while pressing a digit starts over.

Results show 15 significant digits. Computers calculate with binary floating-point numbers, so 0.1+0.2 is 0.30000000000000004 internally; the error sits at the 17th digit and is rounded away on display. If only an error like that is left after an addition or subtraction, such as 0.3−0.1−0.2, the result shows as 0. Numbers of 1E15 and above, and numbers below 0.000001, are shown in scientific notation, like 1E+21 and 1E-7; copy them back into an expression and you can keep calculating. Numbers may have thousands commas, such as 1,234.5, but only in groups of three. The decimal separator must be a point, and 12,5 shows "Incomplete or invalid expression".

Square roots of negative numbers, logs of 0 or a negative number, an input of sin⁻¹ or cos⁻¹ outside −1 to 1, tan 90°, and a negative number raised to a fractional power have no real result and show "Domain error". Dividing by 0 and raising 0 to a negative power show "Cannot divide by 0". Factorial only works for whole numbers from 0 to 170: 171! already exceeds the largest number that can be represented (about 1.8E+308), and any other result above that number shows "Result is too large". ln is the natural logarithm (base e) and log is base 10.

Nothing is uploaded. Each time you get a result with = or Enter, one entry is saved (a lone number is not saved). The same expression is kept only once, as its latest entry, and at most 50 entries are kept. They live only in the localStorage of the current browser on this device, so they are gone if you switch browsers or clear site data. Click "Use" to put an expression back into the calculator; its angle unit is restored too. Ans in an expression is replaced with its value at the time it was recorded. All calculation happens in your browser, and neither expressions nor results are sent anywhere.