Type a number, choose the place to round to and get the rounded value at once. The calculator also shows what each rounding method gives, so you can see when the methods agree and when they differ, such as for a number that sits exactly halfway.
Type the number.
Choose the place to round to, such as tens or 2 decimal places.
Choose a rounding method, or leave it on the usual school rule.
Read the answer and compare the other methods.
School rule: Next digit 0–4: keep. Next digit 5–9: add 1 to the rounding digit.
Round half to even: Exactly halfway: go to the even neighbour (2.5 → 2, 3.5 → 4)
Ceiling / floor: Always go to the larger / smaller neighbour
Rounding, also called rounding off, means replacing a number with a nearby value that is shorter and easier to use. A shop bill of ₹2,536.48 may be read as about ₹2,536, ₹2,540 or ₹2,500 depending on how exact you need to be. The rounding calculator does this for any number and any place value, from millions and lakhs down to six decimal places.
It also shows something most tools hide: there is more than one rule for rounding. They all agree for ordinary numbers and differ only when a value is exactly halfway between two choices, such as 2.5. The calculator lists the answer for nine methods together, including the usual school rule, banker's rounding, ceiling and floor, so you can see which one a textbook, a bank or a computer program has used.
1. Choose the place you are rounding to and underline that digit.
2. Look only at the next digit to its right.
3. If that digit is 0, 1, 2, 3 or 4, leave the underlined digit as it is.
4. If that digit is 5, 6, 7, 8 or 9, increase the underlined digit by 1.
5. Replace every digit after it with zeros, or drop them if they come after the decimal point.
6. If adding 1 turns a 9 into 10, carry the 1 to the digit on the left.
Every number sits between two neighbours at the chosen place. For the tens place, 2,536 sits between 2,530 and 2,540. It is 6 away from the first and 4 away from the second, so it rounds to 2,540. Looking at the next digit is simply a quick way of seeing which neighbour is closer. The rule only needs that one digit, never the ones after it, which is a common source of mistakes.
A number such as 2.5 is exactly in the middle of 2 and 3, so neither is nearer and a rule is needed. Schools teach round half up, giving 3. Banks and scientific work often use round half to even, which picks the even neighbour, giving 2, because always going up would slowly inflate totals. Ceiling and floor ignore nearness completely and always go to the larger or the smaller neighbour.
Computers store most decimals in binary, where a value such as 2.675 cannot be held exactly and is kept as something like 2.67499999. Rounding that to two places gives 2.67 instead of 2.68. This calculator avoids the problem by working directly on the digits you type, the way you would on paper. That makes it a reliable way to check a spreadsheet or a program when the last digit looks wrong.
A school's annual fee collection is ₹48,76,539. The accountant wants to quote it to the nearest lakh in a report.
Find the two nearest values at the hundred thousands (lakhs) place: 4876539 lies between 4800000 and 4900000.
Look at the part being dropped: It is closer to one of them, so most methods agree.
Round half up (the usual school rule): Answer: 4900000
Answer: Rounded number 4900000; Round half down 4900000; Round half to even 4900000
Rounding in stages, such as taking 2.446 to 2.45 and then to 2.5. Round once from the original number, which gives 2.4.
Looking at more than one digit to the right of the rounding place.
Forgetting to carry when a 9 rounds up, for example 3.97 to one decimal is 4.0, not 3.10.
Dropping the trailing zero that shows the accuracy: 4.0 and 4 do not say the same thing.
Assuming negative numbers round the same way in every method. −2.5 rounds to −2 with half up but to −3 with half away from zero.
Giving prices, bills and budgets in round figures.
Reporting marks, percentages and averages to one or two decimal places.
Writing large amounts to the nearest thousand, lakh or crore in reports.
Checking spreadsheet and program results that use a different rounding rule.
School exercises on estimation and place value.
How do I round to 2 decimal places?
Look at the third decimal digit. If it is 5 or more, increase the second decimal digit by 1; otherwise leave it. So 4.786 becomes 4.79 and 4.783 becomes 4.78.
Does 2.5 round to 2 or 3?
By the school rule (half up) it rounds to 3. With banker's rounding (half to even) it rounds to 2, because 2 is even.
How do I round to the nearest lakh?
Choose Hundred thousands (lakhs). 12,56,000 rounds to 13,00,000 because the ten-thousands digit is 5.
Why do banks use round half to even?
Always rounding halves upward pushes totals slightly up over many transactions. Rounding halves to the even neighbour goes up half the time and down half the time, so the errors cancel out.
What is the difference between rounding down and truncating?
For positive numbers they are the same. For negative numbers, rounding down goes to the more negative value (−5.2 → −6), while truncating just drops the digits (−5.2 → −5).