Rounding Calculator

Standard rounding rules

The most common rounding rule is "round half up": if the digit being dropped is 5 or greater, round the preceding digit up; if it is less than 5, leave it unchanged. Rounding 3.456 to two decimal places gives 3.46 because the third decimal (6) is 5 or more.

Some scientific and financial applications use "round half to even" (banker's rounding), which rounds the digit 5 to the nearest even number. This reduces cumulative bias over many rounding operations. Under this rule, 2.5 rounds to 2 and 3.5 rounds to 4.

Rounding to different targets

Rounding to a specific number of decimal places fixes precision after the decimal point. Rounding to significant figures keeps a set number of meaningful digits regardless of the decimal point position. Rounding to the nearest ten, hundred, or thousand replaces lower-order digits with zeros, which is common in population figures, financial summaries, and scientific estimates.