Rounding Calculator
Use our rounding calculator to round a number to any number of decimal places.
Rounded Number:
On this page:
- Calculator
- How to Round Numbers
- Rounding Precision
- Rounding Rules
- How to Round to the Nearest Whole Number
- How to Round to the Nearest Tenth
- How to Round to the Nearest Hundredth
- How to Round to the Nearest Thousandth
- How to Round to the Nearest Ten
- How to Round to the Nearest Hundred
- How to Round to the Nearest Thousand
- Frequently Asked Questions
Joe is the creator of Inch Calculator and has over 20 years of experience in engineering and construction. He holds several degrees and certifications.
Aditya holds a PhD in electrical engineering from Stanford University and specializes in signal processing, algorithms, and machine learning.
How to Round Numbers
Rounding numbers is a way to represent numbers with many significant figures in a simpler form. By simplifying numbers, rounding can make them more manageable to work with and provides a clearer understanding of the scale of the value without sacrificing significant precision.
Rounding helps with approximating values, allowing for quick estimations and informed decision-making when high precision is not required.
Rounding Precision
When rounding a number, you need to figure out what precision you want to round the number to. You can round to the nearest whole number, any number of decimal places, or even the nearest tens, hundreds, or thousands.
The table below shows various levels of precision for rounding.
| Billions | 1,000,000,000 |
|---|---|
| Hundred Millions | 100,000,000 |
| Ten Millions | 10,000,000 |
| Millions | 1,000,000 |
| Hundred Thousands | 100,000 |
| Ten Thousands | 10,000 |
| Thousands | 1,000 |
| Hundreds | 100 |
| Tens | 10 |
| Ones | 1 |
| Tenths | 0.1 |
| Hundredths | 0.01 |
| Thousandths | 0.001 |
| Ten Thousandths | 0.0001 |
| Hundred Thousandths | 0.00001 |
| Millionths | 0.000001 |
| Ten Millionths | 0.0000001 |
| Hundred Millionths | 0.00000001 |
| Billionths | 0.000000001 |
Rounding Rules
When rounding numbers, it is important to keep in mind a set of rules that you need to follow.
- Identify the desired decimal place or whole number precision you want to round to.
- Look at the digit immediately to the right of the desired decimal place or whole number.
- If the digit immediately to the right of the desired decimal place or whole number is 5 or greater, add 1 to the number in the desired decimal place.
- Set all of the numbers to the right of the desired decimal place or whole number equal to 0.
How to Round to the Nearest Whole Number
To round a number to the nearest whole number, you need to follow the rounding rules above. You will be rounding to the nearest number in the ones place.
To do this, look at the number immediately to the right of the number in the ones place, which is the first decimal value. If that value is 5 or greater, then add 1 to the number in the ones place.
Then, set the value to all of the numbers after the decimal equal to 0.
For example, let’s round 4.5639 to the nearest whole number.
Since the first decimal is 5, we need to add 1 to the number in the ones place.
4 + 1 = 5
Then, set the values for the numbers after the decimal equal to 0. This becomes:
5.0000
So, 4.5639 rounded to the nearest whole number is equal to 5.0000, or just 5.
How to Round to the Nearest Tenth
You can round a number to the nearest tenth by following the same rounding rules as before. The only difference is that you will be focusing on the number in the tenths place and immediately to the right of that number.
If the number in the hundredths place (immediately to the right of the tenths place) is 5 or greater, add 1 to the number in the tenths place. Then, set the values of the numbers to the right of the tenths place equal to 0.
For example, let’s round 4.5639 to the nearest tenth.
Since the number to the right of the tenths place is 6, we need to add 1 to the number in the tenths place.
5 + 1 = 6
Then, set the values for the numbers after the tenths place equal to 0. This becomes:
4.6000
So, 4.5639 rounded to the nearest tenth is equal to 4.6000, or simply 4.6.
How to Round to the Nearest Hundredth
You can round a number to the nearest hundredth just as before, but focusing on the number in the hundredths place and the value immediately to the right (i.e. the number in the thousandths place).
If the number in the thousandths place is 5 or greater, add 1 to the number in the hundredths place. Then, set the values of the numbers to the right of the hundredths place equal to 0.
For example, let’s round 4.5639 to the nearest hundredth.
Since the number to the right of the hundredths place is 3, we do not need to add anything to the number in the hundredths place.
The final step is to set the values for the numbers after the hundredths place equal to 0. This becomes:
4.5600
So, 4.5639 rounded to the nearest hundredth is equal to 4.5600, or simply 4.56.
This is the same process that our round to the nearest cent calculator uses to round price values.
How to Round to the Nearest Thousandth
You can round a number to the nearest thousandth using this same technique.
If the number to the right of the thousandths place is 5 or greater, add 1 to the number in the thousandths place. Then, set the values of the numbers to the right of the thousandths place equal to 0.
For example, let’s round 4.5639 to the nearest thousandth.
Since the number to the right of the thousandths place is 9, we need to add 1 to the number in the thousandths place.
3 + 1 = 4
Then, set the values for the numbers after the thousandths place equal to 0.
4.5640
So, 4.5639 rounded to the nearest thousandth is equal to 4.5640, or simply 4.564.
How to Round to the Nearest Ten
You can round a number to the nearest ten by following the same rounding rules as before, but focusing on the number in the tens place.
If the number to the right of the tens place (ones place) is 5 or greater, add 1 to the number in the tens place. Then, set the values of the numbers to the right of the tens place equal to 0.
For example, let’s round 17 to the nearest ten.
Since the number to the right of the tens place is 7 (which is greater than 5), add 1 to the number in the tens place, then set the values for the numbers after the tens place equal to 0.
The number in the tens place is 1, so adding 1 to it makes 1 + 1 = 2. So, 17 rounded to the nearest ten is 20.
Intuitively, the two tens closest to 17 are 10 and 20. The number 17 is closer to 20 (20 – 17 = 3) than it is to 10 (17 – 10 = 7) So, when 17 is rounded to the nearest 10, the result is 20, as calculated above.
This type of intuition can be used to check your answer after rounding.
How to Round to the Nearest Hundred
You can round a number to the nearest hundred by focusing on the number in the hundreds place and to its right.
If the number to the right of the hundreds place (tens place) is 5 or greater, add 1 to the number in the hundreds place. Then, set the values of the numbers to the right of it equal to 0.
For example, let’s round 1,380 to the nearest hundred.
Since the number to the right of the hundreds place is 8, add 1 to the number in the hundreds place, then, set the values for the numbers after the tens place equal to 0.
The number in the hundreds place is 3, so adding 1 to it makes 3 + 1 = 4. So, 1,380 rounded to the nearest hundred is 1,400.
How to Round to the Nearest Thousand
You can round to the nearest thousand by focusing on the number in the thousands place and to the right.
If the number to the right of the thousands place (hundreds place) is 5 or greater, add 1 to the number in the thousands place. Then, set the values of the numbers to the right equal to 0.
For example, let’s round 1,380 to the nearest thousand.
Since the number to the right of the thousands place is 3, you do not need to add anything to the number in the thousands place. Simply set the values to the right of the thousands place equal to 0.
So, 1,380 rounded to the nearest thousand is 1,000.
Frequently Asked Questions
How do you round a negative number?
You round negative numbers the exact same way you round positive numbers. When rounding, ignore the negative sign and treat the number just as a positive number, but be sure to add the negative sign back to the rounded number.
How do you round to the nearest integer?
You can round to the nearest integer by rounding the number to the ones place. If the number in the first decimal position is 5 or greater, then add 1 to the number in the ones place.
Then, remove the decimal portion of the number to get the final result rounded to the nearest integer.
How do you know when to round up?
If the number in the position you are rounding to is followed by 5, 6, 7, 8, or 9, then you will round the number in the position you are rounding to up. Otherwise, you simply replace the numbers after the position you are rounding to with a 0.