Rounding Calculator

Round any number to a specific number of decimal places. Compare round, floor, ceiling, and truncation side by side.

Rounded
Standard rounding (half up)
Floor
Always round down
Ceiling
Always round up
Truncated
Cut off decimals

Rounding Methods

Standard Rounding (Half Up)
If the digit after the rounding position is 5 or more, round up. Otherwise, round down. This is the most common method.
Floor (Round Down)
Always rounds toward negative infinity. For positive numbers, this truncates. For -2.3 → -3.
Ceiling (Round Up)
Always rounds toward positive infinity. For 2.1 → 3. For -2.9 → -2.
Truncation
Simply removes digits after the specified decimal place. Always rounds toward zero.

Examples

3.14159 to 2 decimal places

Rounded: 3.14 | Floor: 3.14 | Ceil: 3.15

-2.75 to 0 decimal places

Rounded: -3 | Floor: -3 | Ceil: -2 | Truncated: -2

Related Calculators

Percentage Calculator
Percent calculations
Scientific Notation
Powers of 10
Average Calculator
Mean, median, mode

Quick Tip

For currency, always round to 2 decimal places. For scientific calculations, round to the number of significant figures in your least precise measurement.