One calculator for everyday and advanced work
This standalone calculator combines two interfaces in one place. Basic mode keeps everyday addition, subtraction, multiplication, and division uncluttered. Scientific mode reveals additional keys for square and cube roots, powers, reciprocals, constants, logarithms, absolute values, and trigonometric functions. The expression stays visible while you work, which makes it easier to catch a missing parenthesis or an incorrect operator before you calculate. Nothing is installed, and an account is not required.
Everyday calculations in Basic mode
Use Basic mode for shopping totals, household budgets, school exercises, and quick workplace arithmetic. The decimal point enters fractional values, the minus key enters subtraction or a negative sign, and parentheses group part of an expression. The percent key divides the preceding value by 100, so 200×10% gives 20. For example, 12.5×4+8÷2 evaluates to 54. If the addition must happen first, enter (12.5+7.5)×4 to get 80. Ans recalls the last successful result so you can continue a multi-step calculation without retyping a rounded display value.
Roots, powers, and functions in Scientific mode
Scientific mode uses function notation that is visible in the display. The √ key inserts sqrt(, ∛ inserts cbrt(, x² appends ^2, x³ appends ^3, and xʸ inserts the general power operator ^. The reciprocal key inserts 1/(, so you should close the parenthesis after the denominator. Use π or e when a constant is required. The log function is base ten, ln is natural logarithm, and abs returns the absolute value. Trigonometric functions depend on the selected angle unit: sin(30) is 0.5 in DEG mode, while RAD interprets 30 as radians.
Operation order and safe evaluation
Parentheses are evaluated first, followed by functions and powers, then multiplication and division, and finally addition and subtraction. Operators at the same level are evaluated from left to right. Because 20÷5×2 means 4×2, write 20÷(5×2) if you intend the denominator to include the multiplication. A dedicated parser accepts only supported numbers, constants, functions, and operators. It does not execute arbitrary code. Invalid syntax, division by zero, negative real square roots, and non-finite results produce an error instead of a misleading number.
Examples you can try
| Expression | Result | Explanation |
|---|---|---|
| (12.5 + 7.5) × 4 | 80 | Parentheses make the addition happen before multiplication. |
| 200 × 10% | 20 | The percent key converts 10% to 0.1 before multiplication. |
| sqrt(81) + 2^3 | 17 | The square root is 9 and the cube is 8. |
| cbrt(27) + 5^2 | 28 | The cube root is 3 and the square is 25. |
| log(100) + ln(e) | 3 | Base-ten log of 100 is 2 and natural log of e is 1. |
| sin(30) in DEG mode | 0.5 | The angle unit is degrees, not radians. |
Check the expression before trusting the answer
A calculator can perform the entered operation correctly even when the expression does not represent the intended question. Read the display from left to right, check every decimal point, and confirm that each opening parenthesis has a closing parenthesis. Estimate the approximate size of the answer before pressing =. For example, a square root of 81 should be near 9, not 90. When continuing with Ans, avoid manually rounding the intermediate result. Save the final displayed value only after checking its unit and meaning; the calculator returns a number, not a currency, measurement unit, or professional recommendation.
A useful practice sequence
Begin in Basic mode with 7÷2 and confirm 3.5. Clear the display, calculate 200×10%, and then use Ans+5 to obtain 25. Switch to Scientific mode and try 9x² for 81, sqrt(81) for 9, and cbrt(27) for 3. Finish with sin(30) after selecting DEG. These short checks demonstrate the main button types and help you distinguish a power, a root, a percentage, and an angle function before attempting a longer expression.
Designed for clear, repeatable use
The two-mode layout avoids showing advanced controls when you only need arithmetic. Large tactile keys work with touch, mouse, and keyboard input, while the separate expression and result lines make corrections straightforward. The interface follows Calcora's light and dark themes, so the display, body, and keys remain readable when your theme preference changes. You can repeat the worked examples to learn the notation, then replace them with your own values and compare scenarios without losing the visible calculation history within the current expression.
Limitations to keep in mind
This is a numerical calculator, not a computer algebra system. It does not simplify symbolic equations, preserve exact symbolic roots, perform statistical regressions, or store a permanent calculation history. Percent means division by 100; for a dedicated percentage-change question, use Calcora's percentage calculator. Floating-point arithmetic can produce tiny representation differences with some decimals. The angle selector affects trigonometric functions only, and the calculator does not infer units or verify that an expression matches a real-world problem.
Frequently asked questions
Where are the old basic and scientific calculator pages?
They have been replaced by this standalone page. Use the mode switch above the calculator to move between Basic and Scientific interfaces.
Does the calculator use eval()?
No. A dedicated parser validates and evaluates only supported mathematical tokens; it does not execute arbitrary JavaScript.
How do I calculate ten percent of 200?
Enter 200×10% and press =. The result is 20. For percentage change or percentage-of-total questions, use the dedicated percentage calculator.
Why does sin(30) change in RAD mode?
Degrees and radians measure angles differently. Thirty degrees has a sine of 0.5; thirty radians is a different angle.
Can I continue from the previous answer?
Yes. Press Ans after a successful calculation to insert the previous result into the current expression.