Free Online Rounding Calculator

Round numbers to decimal places, significant figures, or nearest value

Universal Rounding Calculator

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Quick Reference Guide

Rounding Methods

  • Standard (Nearest): Round to the nearest value (5 rounds up)
  • Round Up: Always round towards positive infinity
  • Round Down: Always round towards negative infinity
  • Banker's Rounding: Round .5 to nearest even number

Examples

  • 123.456 to 2 decimals = 123.46
  • 123.456 to 3 sig figs = 123
  • 123 to nearest 10 = 120
  • 2.5 banker's rounding = 2 (even)

Specialized Rounding Calculators

Rounding Decimals Calculator

Round decimal numbers to any number of decimal places

Round to Nearest Tenth

Round to 1 decimal place (tenths)

Round to Nearest Hundredth

Round to 2 decimal places (hundredths)

Rounding Numbers Calculator

Round to nearest 10, 100, 1000, and more

Round to Whole Number

Round to nearest integer (no decimals)

Significant Figures Calculator

Round to any number of significant figures

Rounding Off Calculator

General purpose rounding tool for all types

Rounding Up Calculator

Always round up (ceiling function)

Rounding Money Calculator

Round currency amounts to cents

Round to Nearest Dollar

Round money to whole dollars

Banker's Rounding Calculator

Round half to even (unbiased rounding)

Rounding Fractions Calculator

Round decimals to nearest fractions

Time Clock Rounding Calculator

Round work hours for payroll

Round to Nearest Cent

Round dollar amounts to the nearest cent

Round to Nearest Hundred

Round numbers to nearest 100

Round to Nearest Ten

Round numbers to nearest 10

Round to Nearest Thousand

Round numbers to nearest 1,000

Round to 2 Decimal Places

Round to exactly 2 decimals

Round to Nearest Thousandth

Round to 3 decimal places

Round to 1 Decimal Place

Round to exactly 1 decimal

Round to 3 Decimal Places

Round to exactly 3 decimals

Round to Nearest Ten Thousand

Round to nearest 10,000

Round to 4 Decimal Places

Round to exactly 4 decimals

Programming Guides

📊

How to Round in Excel

Complete guide to Excel rounding functions: ROUND, ROUNDUP, ROUNDDOWN, MROUND, and more

🐍

How to Round in Python

Learn Python rounding with round(), math.ceil(), math.floor(), Decimal module, and NumPy

How to Round Numbers

Rounding is the process of reducing the number of significant digits in a number while keeping its value close to the original. Here's a step-by-step guide to rounding numbers:

Step 1: Identify the Rounding Place

Determine which digit place you're rounding to (ones, tenths, hundredths, etc.)

Step 2: Look at the Next Digit

Examine the digit immediately to the right of your rounding place

Step 3: Apply the Rounding Rule

  • If the digit is 5 or greater, round up (increase the rounding place by 1)
  • If the digit is less than 5, round down (keep the rounding place the same)

Step 4: Drop Remaining Digits

Remove all digits to the right of the rounding place

Example: Rounding 3.14159 to 2 decimal places

  1. Rounding place is the hundredths place (second digit after decimal): 3.14159
  2. Next digit is 1 (less than 5)
  3. Round down - keep 4 as is
  4. Result: 3.14

Example: Rounding 7.856 to 1 decimal place

  1. Rounding place is the tenths place (first digit after decimal): 7.856
  2. Next digit is 5 (equal to 5)
  3. Round up - increase 8 to 9
  4. Result: 7.9

Rounding Rules

1. Standard Rounding (Round Half Up)

The most common rounding method. If the digit is 5 or greater, round up. Otherwise, round down.

Examples:

  • 2.4 → 2 (4 < 5, round down)
  • 2.5 → 3 (5 = 5, round up)
  • 2.6 → 3 (6 > 5, round up)

2. Round Up (Ceiling)

Always round towards positive infinity, regardless of the following digit.

Examples:

  • 2.1 → 3 (always round up)
  • 2.9 → 3 (always round up)
  • -2.1 → -2 (towards positive infinity)

3. Round Down (Floor)

Always round towards negative infinity, regardless of the following digit.

Examples:

  • 2.9 → 2 (always round down)
  • 2.1 → 2 (always round down)
  • -2.9 → -3 (towards negative infinity)

4. Banker's Rounding (Round Half to Even)

When the digit is exactly 5, round to the nearest even number. This reduces bias in statistical calculations.

Examples:

  • 2.5 → 2 (2 is even)
  • 3.5 → 4 (4 is even)
  • 4.5 → 4 (4 is even)
  • 5.5 → 6 (6 is even)

💡 When to Use Each Method

  • Standard Rounding: General purpose, everyday calculations
  • Round Up: Safety margins, capacity planning, worst-case scenarios
  • Round Down: Budget constraints, conservative estimates
  • Banker's Rounding: Financial calculations, statistical analysis, reducing cumulative errors

Significant Figures Guide

Significant figures (or significant digits) are the digits in a number that carry meaningful information about its precision. Understanding significant figures is essential for scientific calculations and measurements.

What Counts as a Significant Figure?

✓
All non-zero digits

Example: 123.45 has 5 significant figures

✓
Zeros between non-zero digits

Example: 1002 has 4 significant figures

✓
Trailing zeros after a decimal point

Example: 1.200 has 4 significant figures

✗
Leading zeros

Example: 0.0025 has 2 significant figures (only 2 and 5)

?
Trailing zeros in whole numbers (ambiguous)

Example: 1200 could have 2, 3, or 4 sig figs (use scientific notation to clarify)

Examples with Counting
NumberSig Figs
1233
0.01233
1.2304
1000.05
0.001003
Rounding Examples
Original3 Sig Figs
123.456123
0.0123450.0123
1234.51230
0.004560.00456
98769880

🔬 Scientific Notation for Clarity

Use scientific notation to make the number of significant figures unambiguous:

  • 1200 with 2 sig figs = 1.2 × 10³
  • 1200 with 3 sig figs = 1.20 × 10³
  • 1200 with 4 sig figs = 1.200 × 10³

Frequently Asked Questions