Rounding Calculator
Round any number to a chosen precision using multiple rounding modes — half up, half down, half to even (banker's), ceiling, floor and truncate.
How to use the Rounding Calculator
- Enter your inputs into the Rounding Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The rounding modes
Half up: ≥0.5 rounds up · · · Half to even: 0.5 rounds to nearest even (banker's) · · · Ceiling: always up · · · Floor: always down · · · Truncate: drop digits
Different modes handle the exact-half case differently. Half-up is the everyday default; half-to-even is used in finance to avoid systematic upward bias.
Worked example
Round 3.785 to 2 decimal places: half-up → 3.79; half-to-even → 3.78 (because 8 is already even); ceiling → 3.79; floor → 3.78. Round 12,837 to 3 significant figures: 12,800.
Frequently asked questions
What is banker's rounding?
Half-to-even rounding: when the part to round is exactly half, round to the nearest even digit. Eliminates systematic bias when many values get rounded — preferred in financial math.
What's the difference between decimal places and significant figures?
Decimal places count after the decimal point (3.140 has 3 decimal places). Sig figs count meaningful digits including leading non-zero (3.140 has 4 sig figs, 0.00314 has 3).
When should I round?
Final results, not intermediate calculations. Rounding mid-calculation introduces error that compounds. Carry extra digits until the final answer.