Round any number to the nearest thousandth (three decimal places).
How it works
The value is multiplied by 1,000, rounded to the nearest whole number, then divided back by 1,000. 0.12345 rounds to 0.123; 3.14159 rounds to 3.142.
What this does not include
This is distinct from this site’s round-to-the-nearest-hundredth calculator, which rounds to two decimal places instead of three — a thousandth is one level more precise.
How to use this calculator
- Enter a number.
When would you need thousandth-level precision?
Scientific measurements, engineering tolerances, and financial calculations involving small unit prices often call for three decimal places of precision.
Does this work for negative numbers?
Yes — a negative number rounds to the nearest thousandth the same way.
What happens to a value already at exactly three decimal places?
It’s returned unchanged, since it’s already at the target precision.
