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Calculate everyday arithmetic, percentages, powers, and scientific functions with memory keys and a ten-calculation history.
+ / − percentages are relative · angles in degrees
Keyboard: digits and . + - * / ^ % ( ) · Enter or = to calculate · Backspace deletes · Delete clears the entry · Esc clears everything.
Your last ten calculations collect here. Choose one to reuse its result.
Click the number and operation keys, or type digits and operators on your keyboard, then press = or Enter to calculate. Open Scientific for powers, square roots, logarithms, and trigonometry; use your keyboard to enter parentheses when you want to group a calculation. Use ⌫ or Backspace to correct an entry, and C or Escape to start a new expression.
There is no single formula for every expression. The calculator follows order of operations (often called PEMDAS or BODMAS): work inside parentheses first, evaluate functions and powers, then multiply and divide from left to right, and finally add and subtract from left to right. Multiplication does not always come before division: 100 ÷ 10 ÷ 2 is 5, not 20. Use parentheses to make your intended grouping clear.
A percentage means a number divided by 100. In multiplication or division, 25% is 0.25; after + or −, a percentage is taken from the amount on the left, so 80 + 25% means 80 plus 25% of 80. Powers use ^ or the x² key; for example, 2^3 is 2 × 2 × 2 = 8. The √ key finds a nonnegative square root, log uses base 10, and ln uses base e. Sine, cosine, and tangent take angles in degrees.
Answers are displayed to up to 10 significant digits, so repeating decimals and most square roots are rounded decimal values rather than exact fractions. For example, 1 ÷ 3 displays 0.3333333333. Keep exact fractions or symbols in your written working when a question asks for an exact answer.
Enter 2 + 3 × 4. Multiply 3 × 4 = 12, then add 2 + 12 = 14. To add first instead, type (2+3)*4 on your keyboard: the parentheses give 5, and 5 × 4 = 20. The same numbers give different answers because their grouping changes.
An item costs 80 before a 25% discount. First find the saving: 80 × 25% = 80 × 0.25 = 20. Subtract the saving: 80 − 20 = 60. As a shortcut on this calculator, enter 80 − 25% and press = to get the sale price of 60. This calculation does not include any tax or delivery charges.
A right triangle has a 30° angle and a hypotenuse of 10 cm. Sine is opposite ÷ hypotenuse, so the opposite side is 10 × sin(30°). Open Scientific, press sin, enter 30, type a closing parenthesis on your keyboard, then multiply by 10. The expression sin(30) × 10 gives 0.5 × 10 = 5, so the opposite side is 5 cm.
After + or −, the percent key calculates a percentage of the amount on the left: 10% of 100 is 10, so the result is 110. With × or ÷, it uses the percentage as a decimal fraction: 100 × 10% = 10. If you want to add one tenth rather than increase by 10%, enter 100 + 0.1.
Type ( and ) on your keyboard; there are no separate parentheses buttons on the keypad. You can also type * for multiplication and / for division. Scientific function buttons insert an opening parenthesis, and any unclosed parentheses are closed automatically when you calculate. Close a function's parentheses yourself before adding operations that should stay outside it.
It always uses degrees: sin(30) = 0.5 and tan(45) = 1. There is no radians switch. If your angle is in radians, convert it to degrees first by multiplying by 180 ÷ π, then enter that degree value into the trig function.
Division by zero has no defined result, so 1 ÷ 0 shows Error. This calculator works with real numbers: √(−4) is unsupported, log and ln need positive inputs, and tan(90) is undefined. An unfinished expression such as 2 + or an extra closing parenthesis also needs correcting; the message explains the problem.
M+ adds the current expression's value to memory, M− subtracts it, MR inserts the stored number into your expression, and MC resets memory to zero. History keeps the last ten successful calculations; choosing one inserts its result into the current expression, so clear the entry first if you want to start with that number. Use Clear history to remove all history entries without changing your current calculation or memory. C clears the current calculation, not memory or history. Both memory and history reset when you leave this calculator or reload the page; your expressions and results are calculated locally and are not sent to a server.
Use the Fraction Calculator for reduced fractions and fraction working, the Percentage Calculator for discounts and percentage changes with steps, or the Trigonometry Calculator for guided right-triangle problems. To understand why each operation comes next, read the order of operations lesson; the percentages lesson explains the fraction behind a percent. Try the working yourself, then use this calculator to check your answer.