About the Rounding Calculator
This rounding calculator rounds any number to the place value you choose — from six decimal places up to the nearest million. Pick a rounding rule as well: standard half-up rounding (what most schools teach), banker’s rounding (round half to even), always up (ceiling), always down (floor) or simple truncation.
It is useful for homework on place value, for tidying measurements and money amounts, and for checking how spreadsheets or programming languages will round a value. A comparison table shows the same number rounded to every common place so you can see the effect at a glance.
Rounding is done on the decimal digits you type using exact integer arithmetic, so 2.675 rounds to 2.68 at two decimals as you would expect — avoiding the binary floating-point surprise where some software returns 2.67.
With the default inputs, the rounded number is 3.14. Change any value above to recalculate instantly.
How to use the rounding calculator
- 1Type the number you want to round.
- 2Choose the place value, e.g. hundredths for money or nearest thousand for estimates.
- 3Pick a rounding rule — standard half up is right for most schoolwork.
- 4Read the rounded result and the rounding difference.
- 5Use the table to compare the same number rounded to every place.
Formula and method
To round to p decimal places, the number is scaled so the target digit sits in the ones place, the remainder is inspected, and the result is scaled back. For place values left of the decimal point (tens, hundreds, thousands) p is negative, e.g. p = −2 rounds to the nearest hundred.
With half-up rounding, a remainder of exactly one half or more rounds away from zero. Banker’s rounding sends exact halves to the nearest even digit, which removes the upward bias when many values are summed. Ceiling always moves toward positive infinity, floor toward negative infinity, and truncation simply drops the extra digits.
- x
- The number being rounded
- p
- Decimal places to keep (negative for tens, hundreds, thousands)
Worked examples
Round π (3.14159) to two decimals
The hundredths digit is 4 and the next digit is 1, which is less than 5, so the 4 stays and everything after it is dropped: 3.14. The rounded value is 0.00159 smaller than the original.
Round 2.675 to the nearest hundredth
The digit after the hundredths place is exactly 5, so standard half-up rounding bumps 7 up to 8, giving 2.68. Some software shows 2.67 because 2.675 cannot be stored exactly in binary; this calculator rounds the decimal digits you typed.
Round 48,651 to the nearest thousand
The thousands digit is 8 and the hundreds digit is 6 (5 or more), so 48 thousand rounds up to 49,000. The result is 349 more than the original number.
Banker’s rounding of 2.5 to a whole number
Under round-half-to-even, an exact half goes to the nearest even whole number. 2 is even, so 2.5 rounds down to 2 (whereas 3.5 would round up to 4).
Frequently asked questions
How do you round to the nearest tenth?+
Look at the hundredths digit (the second digit after the decimal point). If it is 5 or more, add one to the tenths digit; if it is 4 or less, keep the tenths digit. Then drop all digits after the tenths place, so 7.46 becomes 7.5.
What is banker’s rounding?+
Banker’s rounding (round half to even) rounds an exact half to the nearest even digit: 2.5 → 2, 3.5 → 4. It avoids the slight upward bias of always rounding halves up, which is why it is the IEEE 754 default and is used by many accounting and programming tools.
Does 5 round up or down?+
In the standard half-up rule taught in school, a 5 rounds up (away from zero), so 4.5 becomes 5 and −4.5 becomes −5. Under banker’s rounding, a trailing exact 5 rounds to whichever neighbour is even.
What is the difference between rounding and truncating?+
Rounding looks at the next digit to decide whether to round up, while truncating simply cuts off the extra digits. Truncating 3.99 to one decimal gives 3.9, but rounding it gives 4.0.
How do I round to the nearest hundred?+
Look at the tens digit. If it is 5 or more, round the hundreds digit up; otherwise keep it, then replace the tens and ones digits with zeros. For example, 1,250 rounds to 1,300 and 1,249 rounds to 1,200.