Quickly round decimals or large numbers to the nearest whole integer, tenth, hundredth, or any significant digit setting. Customize the rounding mode with standard, ceil, or floor logic.
How to use the Number Rounding tool?
1. Enter your number: Type any decimal or whole number.
2. Select "Round To": Choose decimal places (tenth, hundredth) or integer multiples (ten, hundred).
3. Select Rounding Mode: Choose how ties and fractions are handled:
- Standard Rounding: Standard math rules. Anything 0.5 or above rounds up, below 0.5 rounds down.
- Round Up (Ceiling): Always pushes the number to the next highest increment.
- Round Down (Floor): Always pushes the number to the lowest increment, removing remainders.
Formula Details
Frequently Asked Questions
Look at the ones digit. If it is 5 or more, add 10 to the tens digit and make the ones digit zero. If it is 4 or less, keep the tens digit the same and make the ones digit zero. (e.g., 87 rounds to 90, 83 rounds to 80).
It means leaving only one digit after the decimal point. Look at the hundredths digit to decide whether to round the tenth digit up or keep it the same.
Ceiling (round up) always increases the value to the next specified increment, regardless of the decimal size. Floor (round down) just truncates any extra value, always decreasing to the lower increment.
19.99 rounded to the nearest tenth is 20.0, because the '9' in the hundredths place pushes the '9' in the tenths place up, causing a carry-over.
Rounding makes numbers simpler and easier to work with or communicate, while keeping their value close to what it originally was. It's heavily used in finance, statistics, and science.