≈ Rounding Calculator

Rounded Result

Rounding Rules

Rounding makes numbers simpler while keeping them close to the original value. The most common rule is "round half up" — if the dropped digit is 5 or greater, round up.

Standard Rounding Rule:
If next digit ≥ 5 → round up
If next digit < 5 → round down

3.146 rounded to 2 decimal places = 3.15
3.144 rounded to 2 decimal places = 3.14

Common Rounding Applications

  • Currency: round prices to 2 decimal places ($3.456 → $3.46)
  • Measurements: round to significant figures for accuracy
  • Statistics: report results to meaningful decimal places

Frequently Asked Questions

How do you round 3.145 to 2 decimal places? ▼
Look at the third decimal: 5. Since it's ≥ 5, round up. 3.145 → 3.15.
What is rounding to the nearest 10? ▼
Look at the ones digit. If ≥ 5, round up to next 10; if < 5, round down. Example: 47 → 50 (7≥5), 43 → 40 (3<5).
What is the difference between rounding and truncating? ▼
Rounding follows the standard rule (≥5 round up). Truncating always cuts off at the specified position without rounding. 3.99 truncated to integer = 3, but rounded = 4.