Rounding Calculator

Round to any place, decimal or significant figure — with half-up, banker's, ceiling, floor and truncate modes — and see exactly which digit decided the answer.

Rounded value —

How Rounding Works

Pick what to round to, then how ties are handled.

1

Enter your number

Type any value, positive or negative, with as many decimals as you like. Commas and spaces are ignored, so pasted figures work fine.

2

Choose what to round to

The nearest whole, ten, hundred or thousand, the nearest tenth or hundredth, or a set number of decimal places or significant figures. The digit just past that point is the one that decides.

3

Pick a mode

Half up is the everyday rule; half to even is banker's rounding; ceiling, floor and truncate never look at the next digit. Working out a volume or measurement instead? The Cubic Feet Calculator gives figures worth rounding.

Frequently Asked Questions

How do I round to the nearest tenth or hundredth?
To round to the nearest tenth, look at the hundredths digit: if it is 5 or more, round the tenths digit up, otherwise leave it. So 3.14159 to the nearest tenth is 3.1, because the next digit is 4. To the nearest hundredth it is 3.14, because the next digit is 1. In this calculator, choose "Nearest tenth" or "Nearest hundredth" from the round-to menu, or pick "Decimal places" and type how many places you want. The tool also tells you which digit decided the result.
What is banker's rounding (round half to even)?
Banker's rounding, or round-half-to-even, breaks ties by rounding to the nearest even digit instead of always rounding a trailing 5 up. So 2.5 rounds to 2 and 3.5 rounds to 4, because 2 and 4 are even. Ordinary rounding would send both up. It exists to remove the small upward bias you get from always rounding halves up, which matters when you sum many rounded values in accounting or statistics. Choose the "Half to even (banker's)" mode to use it here.
How do I round to significant figures?
Significant figures count from the first non-zero digit, regardless of the decimal point. Rounding 12,345 to 2 significant figures gives 12,000, and rounding 0.004567 to 2 significant figures gives 0.0046. It is the standard way to express precision in science and engineering, where the number of meaningful digits matters more than the number of decimal places. Select "Significant figures" in the round-to menu and enter how many figures you want; the calculator handles the scaling for large and small numbers.
What is the difference between rounding, floor, ceiling and truncating?
Rounding goes to the nearest value, up or down. Ceiling always goes up to the next step (so 3.1 becomes 4 for whole numbers), floor always goes down (3.9 becomes 3), and truncate simply drops the extra digits without looking at them (−2.7 becomes −2, toward zero). Floor and truncate differ for negatives: floor of −2.7 is −3, but truncate is −2. This calculator offers all of them as modes, so you can apply the exact behaviour a spreadsheet, tax rule or program expects.