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ISO.CEILING Function

Excel 2007+

Summary

The ISO.CEILING function rounds a number up to the nearest integer or to the nearest multiple of a specified significance, always rounding away from zero regardless of the sign of the number or significance. This follows international mathematical standards for ceiling operations.

Syntax

ISO.CEILING(number, [significance])

Parameters

Parameter	Type	Required	Description
number	`Number`	Yes	The value that needs to be rounded upward
significance	`Number`	No	Optional multiple for rounding. Uses absolute value and defaults to 1.

Using the ISO.CEILING Function

ISO.CEILING provides precise control over upward rounding in Excel formulas. Unlike standard CEILING which can behave differently with negative significance, ISO.CEILING uses the absolute value of significance to ensure consistent mathematical ceiling behavior across all number types.

Common ISO.CEILING Examples

Basic Upward Rounding

=ISO.CEILING(4.3)

Rounds 4.3 up to the nearest integer (5)

Negative Number Rounding

=ISO.CEILING(-4.3)

Rounds -4.3 up to -4 (away from zero)

Custom Multiple Rounding

=ISO.CEILING(4.3,2)

Rounds 4.3 up to nearest multiple of 2 (6)

Negative Significance

=ISO.CEILING(4.3,-2)

Rounds 4.3 up to nearest multiple of -2, which is 6 (absolute value used)

Financial Application

=ISO.CEILING(A1*0.08,0.05)

Rounds sales tax up to nearest nickel for proper billing

Frequently Asked Questions

ISO.CEILING defaults to rounding up to the nearest integer (significance = 1).

ISO.CEILING always uses the absolute value of significance for consistent ceiling behavior, while CEILING can produce different results with negative significance.

ISO.CEILING returns 0 when either the number or significance is 0.

Common Errors and Solutions

#VALUE! Error

Cause: Non-numeric arguments provided

Solution: Ensure both number and significance contain valid numeric values

Unexpected rounding direction

Cause: Expecting standard rounding behavior

Solution: Remember ISO.CEILING always rounds away from zero

Notes

Follows ISO mathematical standards for ceiling functions
Available in Excel 2007 and later versions
Uses absolute value of significance regardless of sign
Essential for international financial calculations

Compatibility

Available in: Excel 2007, Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Microsoft 365

Not available in: Excel 2003 and earlier

Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2007+