Basic Calculator
A full-screen calculator for everyday addition, subtraction, multiplication, and division.
About this calculator
Free Online Basic Calculator
This basic calculator does everyday arithmetic right in your browser — addition, subtraction, multiplication, division and percentages — with a full keypad that works on a phone, tablet or desktop. There is nothing to install and no account needed. A scientific mode adds functions such as powers, roots, logarithms and trigonometry for homework and technical work, and your recent calculations are kept so you can look back at what you did.
How the Order of Operations Works
When an expression mixes operations, calculators follow the standard order: parentheses first, then exponents, then multiplication and division from left to right, then addition and subtraction from left to right. That is why 2 + 3 × 4 equals 14, not 20. Teachers often remember this as PEMDAS or BODMAS. If you want a different order, group that part in parentheses.
What Each Key Does
- C clears the whole entry; the backspace key removes only the last digit.
- ÷ × − + are the four basic operations.
- % turns a number into a percentage of another — for example, 200 + 10% adds ten percent of 200.
- = finishes the calculation and shows the result, which you can keep using in the next one.
Handy Tips for Accurate Results
- Check division by zero — it is undefined, and the calculator will warn you instead of returning a number.
- Very long decimals are rounded for display. Use the Rounding Calculator when you need a specific number of decimal places.
- For fractions, ratios and percent problems, a dedicated tool such as the Fraction Calculator or the Percentage Calculator is faster than doing it by hand on a keypad.
Where a Basic Calculator Helps Most
Budgeting, splitting a bill, converting a recipe, checking a receipt, doing homework, or estimating materials for a project are all quick jobs for a basic calculator. For loan, health and science questions, browse the rest of the site — there is likely a purpose-built calculator that already knows the formula.
Worked example
Like a physical calculator, operations chain left to right as you enter them rather than following algebraic order of operations: 6 + 4 = 10, then pressing × 3 multiplies that running total, giving 30 — not the 18 you'd get by calculating 4 × 3 first.
Frequently asked questions
Does this follow order of operations (PEMDAS)?
No — like most physical calculators, it evaluates left to right as you press keys. Entering 2 + 3 × 4 gives (2+3)×4 = 20, not the algebraic 14.
What does the % key do?
It divides the current display value by 100 in place, so you can chain it into a running calculation — useful for quick percentage math like tips or discounts.
Why does dividing by zero show an error?
Division by zero is undefined, so the calculator shows an error state instead of a number rather than silently returning something misleading.
Can I use my keyboard instead of clicking?
Yes — number keys, +, -, *, /, Enter (=), and Backspace all work directly, matching the on-screen buttons.
