What is the difference between floor and truncate?

Truncate always removes the extra digits toward zero. Floor always rounds toward negative infinity. For positive numbers they produce the same result, but for negative numbers they differ: truncate(-2.7) = -2, while floor(-2.7) = -3.

What does standard rounding (half up) mean?

Standard rounding rounds the digit up when the next digit is exactly 5 or higher. For example, 2.5 rounds to 3, and 2.45 rounded to 1 decimal place gives 2.5.

Can I round to 0 decimal places to get a whole number?

Yes. Set the decimal places to 0 to round to the nearest whole number using any of the four modes.

What is ceiling rounding?

Ceiling always rounds toward positive infinity, regardless of the fractional part. For example, ceil(2.1) = 3 and ceil(-2.9) = -2.

Does this tool handle very large or very small numbers?

Yes. JavaScript numbers support up to about 15-17 significant digits. For very large numbers, scientific notation (e.g. 1.5e10) is also accepted.

Rounding Calculator

Name: Rounding Calculator
Availability: InStock
Author: Nham Vu

Enter a number, choose a rounding mode, and instantly see the result rounded to your chosen decimal places.

Rounding Settings

Number

Decimal Places

Rounding Mode

Standard Floor Ceiling Truncate

Result

Enter a number on the left to see the result.

All Modes Comparison

Enter a number to compare all rounding modes.

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Summary

Enter a number, choose a rounding mode, and instantly see the result rounded to your chosen decimal places.

How it works

Enter the number you want to round in the input field.
Choose the number of decimal places (0 for whole numbers).
Select a rounding mode: Standard, Floor, Ceiling, or Truncate.
The rounded result appears instantly.
Click Copy to copy the result to your clipboard.

Use cases

Round currency values to 2 decimal places for billing.
Round scientific measurements to significant decimal places.
Floor or ceiling prices to the nearest dollar.
Truncate long decimals without rounding for data processing.
Compare results across all four rounding modes at once.
Round percentages to 1 or 2 decimal places for reports.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu