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CalculatorBuddy

Rounding Calculator

Round a number to decimal places, place values, common fractions, or a custom precision using nine rounding methods.

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ExampleSample values — edit any field to see your result.

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Rounded Result

3.142

Estimated result

Rounded Number
3.142
Rounding Difference
0.0004074
Rounding Rule
Round to the nearest (default); 3 decimal places

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Rounded Result3.142

Round to common decimal places, large place values, or fractional increments. Choose among nine rounding methods, including different ways to handle ties. A second mode accepts a custom decimal-place precision from -1000 to 1000.

How to use this calculator

Enter the original value with all available digits, then choose the rounding place and method. Round once at the end of a calculation to avoid accumulating rounding error. Check whether the requested place is a decimal place or a power of ten.

Examples

Round pi to thousandths

Rounding 3.1415926 to three decimal places gives 3.142.

Round to an eighth

15.65 rounds to the nearest 1/8 as 15.625.

Formula

For increment q, the calculator rounds number / q according to the selected rule, then multiplies by q. Decimal precision p uses q = 10^(-p).

Rounding limits

The selected rule is applied at one stated place. Values exactly halfway between representable decimal steps are sensitive to the tie rule, and binary floating-point storage can make a typed decimal fall just above or below an apparent tie. Financial, tax, and measurement standards may require a particular rule and a particular stage at which rounding occurs.

Frequently asked questions

Which rounding methods are supported?
Nearest, half up, half down, ceiling, floor, half to even, half to odd, half away from zero, and half toward zero.
Can I round to a fraction?
Yes. Presets include the nearest half, quarter, eighth, sixteenth, thirty-second, and sixty-fourth.
What does a negative decimal precision mean?
It rounds to a place left of the decimal point; -1 means tens, -2 hundreds, and -3 thousands.
What is bankers rounding?
Round half to even is often called bankers rounding. Exact halfway values go to the neighboring even value to reduce cumulative bias.

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