Basic Calculator
A clean four-function calculator with percentage and memory keys.
About Basic Calculator
This calculator performs standard four-function arithmetic on two numbers. The optional percent mode follows the convention of physical calculators: for addition and subtraction the second number is treated as a percentage of the first (so 200 + 15% adds 30, not 0.15); for multiplication and division it divides by 100 first.
Formulas
Addition
Result = A + B
- A
- First operand
- B
- Second operand
Percent-of add
Result = A + (B% × A) when percent mode is on
- A
- First operand
- B
- Percent value
Worked example
With the default values below, Basic Calculator returns Result of 215.0000000000. Change any input above and every figure here is recalculated in your browser.
Inputs used
- First number
- 200
- Operationone of Add (+), Subtract (−), Multiply (×), Divide (÷)
- Add (+)
- Second number
- 15
- Treat second number as a percent (%)
- No
Results
- Result
- 215.0000000000
Step by step
- 1Inputs= A = 200, B = 15
- 2Apply operation= 215
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 10 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
What does the percent toggle do on addition?
It converts the second number into a percentage of the first before adding. So 200 + 15% means 200 + (15% of 200) = 200 + 30 = 230 — the same as most physical calculators and spreadsheets.
Why does 1 ÷ 3 show many decimal places?
The result is a repeating decimal (0.333…). The calculator shows up to 10 decimal places so you can see the precision. For exact results, use the Fraction Calculator instead.
Can I chain multiple operations?
This calculator is intentionally designed for one operation at a time. For chained expressions, use the Scientific Calculator which supports a full expression parser.