Round any number to decimal places, to the nearest ten, hundred or thousand, or to significant figures, using the half-up rule with the working shown. Runs entirely in your browser — your numbers never leave this device.
| Rounding | Result |
|---|---|
| 0 places | 4,383 |
| 1 place | 4382.7 |
| 2 places | 4382.68 |
| 3 places | 4382.675 |
Half away from zero: a cut digit of exactly 5 rounds the kept digit up in magnitude — so 2.5 rounds to 3 and −2.5 rounds to −3.
| Round 4,382.675 to | Result |
|---|---|
| Nearest 1,000 | 4,000 |
| Nearest 100 | 4,400 |
| Nearest 10 | 4,380 |
| Nearest whole number | 4,383 |
| 1 decimal place | 4,382.7 |
| 2 decimal places | 4,382.68 |
| 3 significant figures | 4,380 |
| 4 significant figures | 4,383 |
Rounding replaces a number with a nearby, simpler one, and there are three everyday ways to choose the target. Decimal places count digits after the point, which is what money and measurements usually need. Place value rounds to the nearest 10, 100, 1,000 and so on, which suits population figures and large estimates. Significant figures count digits from the first non-zero digit onwards, which is the right tool when the size of the number varies — it keeps the same relative precision for 12,749 and for 0.004567, where a fixed number of decimal places would be meaningless for one of them. Pick a mode, pick a precision, and the calculator shows which digit decided the rounding.
All three modes here use the half-up rule taught in schools: when the dropped part is exactly half of the last kept unit, the number rounds up — for negative numbers, half away from zero, so −2.5 rounds to −3 just as 2.5 rounds to 3. The calculator states this rule openly because it is a choice, not a law of nature: banks and statistics software often use round-half-to-even (bankers' rounding) instead, under which 2.5 would round to 2. If your answer differs from a spreadsheet's by one in the last digit, a different tie rule is the usual explanation.
One honest warning about the famous case 2.675. Computers store decimals in binary floating point, and 2.675 cannot be stored exactly — inside the machine it is actually 2.67499999…, a hair below the halfway point, so naive computer rounding gives 2.67. The textbook answer is 2.68, because in decimal the digit after the hundredths place is exactly 5 and half-up applies. This calculator does the rounding in decimal arithmetic, the way you would on paper, so it returns 2.68 — and this page tells you why other tools sometimes disagree.
Decimal places count from the decimal point; significant figures count from the first non-zero digit. The number 0.0046 has 4 decimal places but only 2 significant figures, while 4,383 has 0 decimal places and 4 significant figures. Use decimal places when the unit is fixed (money, centimetres) and significant figures when you want the same relative precision across very different sizes.
It is the rule for the exact halfway case. When the dropped part is precisely half of the last kept unit, the kept digit goes up in magnitude: 2.5 → 3, 2.675 → 2.68 at two decimal places, and −2.5 → −3, away from zero rather than towards positive infinity. It is the rule most school courses teach, and the one this calculator uses in every mode.
Because of binary floating point. Your spreadsheet stores 2.675 as the nearest binary fraction, which is 2.67499999… — just below the halfway point — so its rounding rule, whatever it is, sees a number that is not quite half and rounds it down. The value was changed by the storage format before rounding even began. This calculator rounds in decimal, so it gives the textbook 2.68.
No. Round-half-to-even (bankers' rounding) sends exact halves to the nearest even digit — 2.5 → 2 but 3.5 → 4 — which cancels out bias over large data sets and is the default in many statistics and programming tools. Truncation simply drops digits without rounding at all. Different rules explain most one-digit disagreements between calculators; this page uses half-up throughout and says so.
Count from the first non-zero digit. To 2 significant figures, keep the 1 and the 2 and look at the next digit, 7, which rounds the 2 up to 3, giving 13,000. To 3 significant figures you keep 127 and the next digit, 4, leaves it unchanged, giving 12,700. Notice that 3 significant figures and 'nearest 100' agree here — they often do for numbers of this size, but they are different rules and diverge for small decimals.
No. This calculator runs 100% in your browser — the numbers you type are rounded locally on your device, nothing is uploaded, saved or tracked, and closing the page clears everything.
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