Rounding Numbers Calculator

Round numbers up or down to any decimal place. Round to nearest dollar (ones) or cent (hundredths).

Round numbers to any decimal place or whole number. Choose ones for dollars, hundredths for cents.

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Max 20 characters

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help_outlineHow to Useexpand_more

Basic Rounding Rules

When rounding to any place value, the steps are the same: identify the place value you're rounding to, then look at the digit to the right. Round ones to get the nearest dollar. Round hundredths to get the nearest cent.

Identify the place value you're rounding to
Look at the next smallest place value (the digit to the right)
If that digit is 0-4, round down (keep the digit the same)
If that digit is 5-9, round up (increase the digit by 1)
Replace all digits after the rounding position with zeros (or drop decimal digits)

Rounding the Same Number to Different Places:

For the number 838.274:

To nearest hundred → 800
To nearest ten → 840
To nearest one → 838
To nearest tenth → 838.3
To nearest hundredth → 838.27

infoWhat is Rounding Numbers Calculator?expand_more

Rounding is the process of replacing a number with an approximate value that has fewer significant digits. The smaller the place value you round to, the more accurate your result will be.

This calculator uses the Round Half Away From Zero method, which is the standard rounding method taught in schools. When the deciding digit is exactly 5 (the halfway point), the number rounds away from zero—positive numbers round up, negative numbers round down (become more negative).

Common uses: Rounding currency to dollars (ones) or cents (hundredths), simplifying calculations, expressing measurements with appropriate precision, and making numbers easier to work with mentally.

functionsFormulaexpand_more

Standard Rounding Rules:

Look at the digit immediately after your rounding position:

• Digits 0, 1, 2, 3, 4 → Round DOWN

• Digits 5, 6, 7, 8, 9 → Round UP

Rounding Positive Numbers:

2.4 rounds down to 2

2.5 rounds up to 3 (halfway, rounds away from 0)

2.6 rounds up to 3

Rounding Negative Numbers:

-2.4 rounds up to -2 (toward zero)

-2.5 rounds down to -3 (halfway, away from 0)

-2.6 rounds down to -3

lightbulbExamplesexpand_more

Example 1: Round 3250 to Nearest Hundred

Identify hundreds digit: 2 in 3250

Look at next digit (tens): 5

5 ≥ 5, so round up: 2 becomes 3

3250 → 3300

Example 2: Round 499 to Nearest Ten

Identify tens digit: first 9 in 499

Look at next digit (ones): 9

9 ≥ 5, so round up: 9 becomes 10 (carry the 1)

499 → 500

Example 3: Round 0.74 to Nearest Tenth

Identify tenths digit: 7 in 0.74

Look at next digit (hundredths): 4

4 < 5, so round down: 7 stays the same

0.74 → 0.7

Example 4: Round 3.141 to Nearest Hundredth

Identify hundredths digit: 4 in 3.141

Look at next digit (thousandths): 1

1 < 5, so round down: 4 stays the same

3.141 → 3.14

quizFAQexpand_more

Why does 5 round up instead of down?expand_more

The digit 5 is exactly at the halfway point. In the 'Round Half Away From Zero' method (standard rounding), halfway values round away from zero. This means positive numbers round up and negative numbers round to a more negative value. This ensures consistent behavior across positive and negative numbers.

How do I round money to the nearest dollar or cent?expand_more

To round to the nearest dollar, round to the ones place. For $15.49, look at the tenths (4), which is less than 5, so it rounds to $15. To round to the nearest cent, round to the hundredths place. For $15.496, look at the thousandths (6), which rounds up to $15.50.

What happens when rounding causes a 'carry over'?expand_more

When rounding up causes a digit to become 10, you carry over to the next place. For example, 499 rounded to the tens: 9+1=10, so it carries over making 500. Similarly, 9.97 rounded to tenths: 9+1=10, so it becomes 10.0.

What is the difference between rounding and truncating?expand_more

Rounding considers the next digit to determine whether to round up or down. Truncating simply removes digits without consideration—3.789 truncated to tenths is 3.7, but rounded to tenths is 3.8. Truncating always goes toward zero.

What is banker's rounding?expand_more

Banker's rounding (round half to even) rounds 5 to the nearest even number to reduce bias over many calculations. So 2.5 rounds to 2, but 3.5 rounds to 4. This calculator uses standard rounding where 5 always rounds away from zero.