Free online calculator · Math
Standard Calculator
Perform basic arithmetic including addition, subtraction, multiplication, division, percentages and square roots.
Formula • Worked example • Interpretation
Basic arithmetic, percentages and operation order
Use the standard calculator for everyday addition, subtraction, multiplication, division and percentages. You can enter a sequence using the keypad or supported keyboard keys.
Calculation method
Addition combines values; subtraction finds a difference; multiplication scales a value; division splits it into equal parts. Follow the calculator’s displayed operator behavior for multi-step expressions.
Worked example
To calculate 12 × 8 + 4, enter 12, multiply, 8, add, 4, then equals. The result is 100 when standard multiplication-before-addition precedence is applied.
What your result means
Use the backspace key to correct a digit and clear to start again. For scientific notation, logarithms, or trigonometry, switch to the scientific calculator.
Tips for better calculations
Use the percentage calculator for percentage change and reverse percentages; the standard percent key may behave differently depending on expression context.
Assumptions and limitations
Division by zero is undefined. Floating-point representations may round repeating decimals. Confirm the tool’s operator-precedence behavior when combining several operations.
SiCalcs tools provide estimates and educational calculations; they do not replace professional financial, medical, tax, or legal advice.