Math & Algebra Tool

Rounding Calculator

Round numbers to significant figures.

Σ The Formula

Round to n decimal places or significant figures

Real World Examples

Decimal Places
3.14159 to 2 places → 3.14
Whole Number
47.6 → 48
Significant Figures
12345 to 2 sig figs → 12000
Nearest 10
87 → 90

# About This Calculator

Rounding is the process of simplifying a number by keeping its value close to what it was but making it easier to read or use.

Common methods include:
Standard (Half Up): If the next digit is 5 or more, round up. Otherwise, round down.
Decimal Places: Limiting digits after the dot (e.g. currency to 2 places).
Significant Figures: Keeping only the most meaningful digits.

This tool allows precise control over how you want to round your numbers for math homework, financial reports, or scientific data.

How To Use

  1. Enter the Number to round.
  2. Enter the target Precision (e.g., 2 for two decimal places).
  3. Select the Mode (Decimal Places or Significant Figures).
  4. Click Round.

Frequently Asked Questions

What is the rule for rounding 5?+

In standard 'Half Up' rounding, a 5 rounds UP. So 2.5 becomes 3. (Note: bankers sometimes use 'Round to Even' for 5s to reduce bias).

What is truncating?+

Truncating simply cuts off extra digits without looking at them. 2.9 truncated to a whole number is 2, whereas rounded it would be 3.

Difference between Sig Figs and Decimals?+

Decimal places count digits AFTER the point. Sig Figs count ALL meaningful digits from the first non-zero digit.

Why do we round?+

To make numbers easier to communicate and understand, or because the extra precision is experimental noise/error.

What is Floor and Ceiling?+

Floor always forces rounding DOWN (3.9 -> 3). Ceiling always forces rounding UP (3.1 -> 4).

Is Rounding Calculator free to use?+

Yes, Rounding Calculator on Matheric is completely free to use. We believe in accessible education and utility for everyone.

About

Rounding is the process of simplifying a number by keeping its value close to what it was but making it easier to read or use.

Common methods include:
Standard (Half Up): If the next digit is 5 or more, round up. Otherwise, round down.
Decimal Places: Limiting digits after the dot (e.g. currency to 2 places).
Significant Figures: Keeping only the most meaningful digits.

This tool allows precise control over how you want to round your numbers for math homework, financial reports, or scientific data.

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