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Rounding Calculator

Round any number to the nearest whole number, nearest tenth, hundredth or thousandth, or to the nearest 10, 100 or 1000 — instantly and privately. Choose a mode, type your number, and this free rounding calculator returns the rounded value, the amount it changed by, and the rule it applied. Everything happens in your browser, so nothing is uploaded.

Round to

Number to round

Who is this rounding calculator for?

A rounding calculator quickly removes unwanted precision from a number, turning raw figures into clean, usable values. It is a go-to tool for anyone who works with numbers.

Students: round decimals and measurement answers, check rounding homework, and tidy up long results from calculations.
Teachers: build rounding exercises, set answers, and show learners exactly how round-half-up rules change a number.
Accountants and analysts: round money to cents, round quantities to sensible scales, and round projections to the nearest 10 or 100 for clean estimates.
Anyone doing quick estimates: turn 16.43 into 16, or 48,812 into 49,000, to make a number easier to read, compare and say out loud.

Rounding examples at different precisions

Each row shows the same kind of rounding the calculator performs, using the round-half-up rule (halfway values move away from zero).

Input	Round to	Rounded	Rounded by
3.14159	Whole number	3	0.14159
3.14159	Nearest tenth	3.1	0.04159
3.14159	Nearest hundredth	3.14	0.00159
3.14159	Nearest thousandth	3.142	0.00041
9.999	Whole number	10	0.001
1289	Nearest 10	1290	1
1289	Nearest 100	1300	11
1289	Nearest 1000	1000	289
2.5	Whole number	3	0.5
-2.5	Whole number	-3	0.5

Notice the last two rows: with round half up, both 2.5 and -2.5 move away from zero, so they become 3 and -3 respectively.

What is rounding?

Rounding means expressing a number with fewer decimal places or at a coarser scale, while keeping it close to the original value. Instead of carrying around every digit, you keep only the precision you actually need. The standard rule used here is round half up: if the part you are discarding is exactly halfway, you round away from zero. So 2.5 rounds to 3, and -2.5 rounds to -3. If the discarded part is below half, you round down; if it is above half, you round round up.

To round to a decimal place, look at the digit immediately to the right. For the nearest hundredth (two decimal places), 3.14159 becomes 3.14 because the third decimal digit is a 1, below 5. For the nearest whole number, 3.14159 becomes 3. To round to a place such as the nearest 10, 100 or 1000, the same idea applies to the digits on the left of the decimal point — 1289 to the nearest 10 becomes 1290. Rounding is everywhere: money to cents, measurements to sensible ticks, estimates to round figures. This calculator applies the same consistent rule so you always know how a number was rounded.

How to use

Pick the precision you want from the Round to menu.
Enter the number you want to round — decimals and negatives work.
Click Round it to see the rounded value, the difference, and the rule used.

Example

Enter 3.14159 and choose nearest hundredth (0.01). The calculator returns 3.14, since the third decimal place is 1, which is below 5, so the value rounds down. The amount rounded by is 0.00159. Switch to nearest tenth and the same number becomes 3.1, or to nearest whole number and it becomes 3.

Common use cases

Rounding money to the nearest cent (hundredth) for invoices and totals.
Rounding measurements and lab results to a sensible number of decimal places.
Rounding large figures to the nearest 10, 100 or 1000 to build quick estimates.
Tidying up long calculator output before you write it in a report or answer.

Pro tips

Round once at the end of a multi-step calculation instead of at every step to avoid drift.
Keep full precision for money sums and only round the final displayed amount.
Round half up ties away from zero; if your work needs round-half-even, use a different rule.
For a good estimate, round large numbers to one or two significant digits first.

Rounding Calculator FAQs

What is round half up?

Round half up means that when a value sits exactly halfway between two options, it rounds away from zero: 2.5 becomes 3 and -2.5 becomes -3.

How do I round to 2 decimal places?

Choose the nearest hundredth (0.01) mode. For example, 3.14159 rounds to 3.14.

How do I round to the nearest whole number?

Use the nearest whole number mode. 3.14159 becomes 3, while 9.999 rounds up to 10.

How do I round to the nearest 10, 100 or 1000?

Pick the matching mode. 1289 to the nearest 10 is 1290, to the nearest 100 is 1300, and to the nearest 1000 is 1000.

What is the difference between the nearest tenth and the nearest hundredth?

The tenth is one decimal place (0.1) and the hundredth is two (0.01). 3.14159 to the nearest tenth is 3.1, and to the nearest hundredth is 3.14.

What does the amount rounded by mean?

It is the difference between the original number and the rounded result. For 1289 rounded to the nearest 10, the gap is 1 because the result is 1290.

How does this calculator handle negative numbers?

It uses round half up, so halfway values move away from zero. For example, -2.5 rounds to -3 and -3.75 to the nearest tenth becomes -3.8.

What is a decimal place?

A decimal place is a position after the decimal point: tenths, hundredths and thousandths. The number of places sets the precision you are rounding to.

Is this rounding calculator free and private?

Yes. It is completely free, runs entirely in your browser, and no data is uploaded.