Round numbers to a specified precision
This rounding calculator allows you to round numbers to a specified number of decimal places or significant figures. It shows both the original and rounded values side by side with an explanation of the rounding process.
Rounding replaces a number with a shorter, simpler approximation that is close to the original value. The standard rule is to look at the digit immediately to the right of the desired precision: if it is 5 or greater, round up; otherwise, round down (truncate).
Decimal places count digits after the decimal point. Significant figures count all digits from the first non-zero digit, regardless of decimal position. For example, rounding 0.003456 to 2 decimal places gives 0.00, but to 2 significant figures gives 0.0035.
Significant figures are commonly used in scientific and engineering contexts to reflect measurement precision. They ensure that calculated results do not imply greater accuracy than the original measurements. Decimal places are more common in everyday arithmetic and finance.