Round to the Nearest Thousandth – Online Calculator and Rules

Round any number to the nearest thousandth (3 decimal places). 3.14159 rounds to 3.142; 2.71828 rounds to 2.718.

How to round to the nearest thousandth

Keep three digits after the decimal point and look at the fourth: if it is 5 or more, round the third digit up; otherwise leave it. Half-values round up.

Common mistake

Truncating instead of rounding. 3.14159 truncated is 3.141, but rounded to the thousandth it is 3.142.

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