Use our Rounding Calculator to quickly round any number to the nearest integer, to a chosen number of decimal places, to a set count of significant figures, or even to the nearest custom multiple. It supports popular tie-breaking rules like half up, half down, and banker's rounding (half even), so you get the exact behavior you need for math, finance, science, or everyday use.
What the Rounding Calculator does
Rounding makes numbers simpler while keeping them close to the original value. Whether you need to present clean figures, standardize measurements, or meet a reporting guideline, the Rounding Calculator gives you precise control. Choose from several methods depending on your task:
- Nearest integer: Round to whole numbers for quick estimates and counts.
- Decimal places: Fix the number of digits after the decimal point for prices, measurements, and reports.
- Significant figures: Keep the most meaningful digits for scientific and engineering calculations.
- Nearest multiple: Snap values to increments like 0.05, 0.5, 5, 25, or any custom step.
- Always up (ceiling) or always down (floor): Enforce strict bounds for compliance or capacity limits.
How to use the calculator
- Enter the number you want to round.
- Select the rounding method that matches your goal.
- If needed, provide extra details such as decimal places, significant figures, or the nearest multiple.
- Choose a tie-breaking rule for halfway cases: half up, half down, or half even (banker’s rounding).
- Click Calculate to see the result instantly.
Choosing the right tie-breaking rule
Halfway values occur when a number sits exactly between two candidates, like 2.5 between 2 and 3 or 1.245 between 1.24 and 1.25 (to two decimals). The Rounding Calculator offers these options:
- Half up: 2.5 becomes 3; a familiar default in many contexts.
- Half down: 2.5 becomes 2; useful when you want a conservative bias.
- Half even (banker’s): 2.5 becomes 2, 3.5 becomes 4; reduces cumulative bias in large datasets.
When to round to decimal places vs. significant figures
Rounding to decimal places fixes how many digits appear after the decimal point. This is common in finance (e.g., two decimals for currency) and in formatting outputs for reports. Rounding to significant figures keeps a set number of meaningful digits regardless of magnitude, which is ideal for scientific data where measurement precision matters across a wide range of values.
Examples
- Nearest integer: 12.6 ? 13 (half up)
- Two decimal places: 3.14159 ? 3.14 (half even might produce 3.14 or 3.15 depending on the third decimal)
- Three significant figures: 0.0012345 ? 0.00123; 12345 ? 1.23 × 104 (displayed as 12300 when rounded)
- Nearest multiple of 0.05: 2.37 ? 2.35 (or 2.40, depending on the tie-breaking rule)
- Ceiling and floor: 4.01 ? 5 (ceiling), 4.99 ? 4 (floor)
Why rounding matters
Rounding improves readability, reduces noise, and helps you follow standards. In finance, it avoids tiny cent-level discrepancies. In science and engineering, it reflects the precision of instruments and prevents misleading exactness. In data visualization, it keeps labels clean and comparable. The Rounding Calculator centralizes these needs with flexible options so you can work faster and with confidence.
Tips for best results
- Pick a tie-breaking rule and use it consistently across your dataset to avoid bias.
- For measurements, match significant figures to the precision of your instruments.
- Use nearest multiples to enforce price ticks, packaging sizes, or scheduling blocks.
- When in doubt, half even is a good default for large aggregates because it balances rounding up and down.
Whether you are formatting a report, cleaning data, or preparing numbers for presentation, the Rounding Calculator offers an accurate, transparent, and repeatable process for every rounding scenario.