Rounding calculator

Rounding rules

Look at the digit after the rounding place. If 5 or more, round up. If less than 5, round down.

Examples

3.14159 to 2 decimal places: look at 3rd decimal (1) → round down → 3.14.

3.14159 to 4 places: look at 5th decimal (9) → round up → 3.1416.

Rounding to significant figures

Count from the first non-zero digit. 0.00450 has 3 sig figs. 3.14 rounded to 2 sig figs = 3.1.