ISO.CEILING Function

Excel Functions › Math & Trig

Excel 2013+ Math & Trig

The Excel ISO.CEILING function rounds a number up to the nearest multiple of significance, always toward positive infinity — the ISO-standard ceiling that's functionally identical to CEILING.PRECISE.


Quick answer:
=ISO.CEILING(-4.3) up toward zero = -4

Syntax

=ISO.CEILING(number, [significance])
ArgumentDescription
numberRequiredThe value you want to round up.
significanceOptionalThe multiple to round to. Its sign is ignored. Defaults to 1.

How to use it

ISO.CEILING always rounds up toward positive infinity and ignores the sign of significance, so mixed signs never cause an error:

=ISO.CEILING(4.3) // next integer = 5
=ISO.CEILING(-4.3) // up toward zero = -4
=ISO.CEILING(23, 5) // next multiple of 5 = 25

For negatives, rounding up means moving toward zero, so -4.3 becomes -4. The result is the same as CEILING.PRECISE in every case.

ISO.CEILING vs CEILING.PRECISE: they return identical results. ISO.CEILING is provided for compatibility with the ISO/ODF spreadsheet standard; pick whichever name reads better in your workbook.

Try it: interactive demo

Live demo

Pick a ISO.CEILING example to see the formula and its result.

Result:

Practice workbook

📊
Download the free ISO.CEILING practice workbook
Every example on this page, ready to open in Excel — plus practice challenges with answers on a separate tab. No sign-up required.

Frequently asked questions

Is ISO.CEILING the same as CEILING.PRECISE?
Yes — they are functionally identical: both round up toward positive infinity and default significance to 1. ISO.CEILING exists for ISO/ODF compatibility.
Why does ISO.CEILING(-4.3) give -4?
Rounding up means toward positive infinity, which for a negative number is toward zero, so -4.3 rounds up to -4.
Does the sign of significance affect ISO.CEILING?
No — the sign is ignored. =ISO.CEILING(23, -5) returns 25, exactly like =ISO.CEILING(23, 5).
How does ISO.CEILING differ from classic CEILING?
Classic CEILING rounds toward zero for negatives and errors when signs differ. ISO.CEILING always rounds toward positive infinity and never errors on signs.

Master functions like this in one day

This page covers one function. Our Excel Formulas and Functions class covers the 30 that matter most — live, hands-on, taught by professionals in Dallas–Fort Worth, Houston, Austin, Oklahoma City, Denver, or online.

See the Formulas & Functions Class

Related functions: CEILING.PRECISE · CEILING · CEILING.MATH · FLOOR.PRECISE · ROUNDUP