Rounding Calculator
Round numbers using 5 modes: round half up, banker's rounding, floor, ceil, and truncate. Shows step-by-step explanation with the digit being rounded. Numbers never leave your device — every calculation runs locally in your browser.
How to Use the Rounding Calculator
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Frequently Asked Questions
What is banker's rounding?
Banker's rounding (round half to even) rounds exact .5 ties to the nearest even number: 2.5 → 2 and 3.5 → 4. Non-ties round normally (2.4 → 2). Use it for statistical and financial data to avoid upward bias.
What's the difference between floor, ceil, and truncate?
Floor rounds toward −∞ (−3.7 → −4), ceil rounds toward +∞ (−3.7 → −3), and truncate simply drops decimals (−3.7 → −3). For positive numbers, floor = truncate. They differ for negative numbers.
Why does the step display matter?
It shows you exactly which digit is being rounded and why the result is what it is. For example, rounding 3.145 to 2 places: the third decimal digit is 5, so round-half-up rounds up to 3.15.
When should I use each rounding mode?
Round half up: everyday math. Banker's rounding: statistical/financial data. Floor: when you need the lower bound. Ceil: when you need the upper bound. Truncate: when you need to drop decimals without rounding (e.g., integer division).
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Last updated October 2026