How many IFs can be nested?

Up to 64, but beyond three the formula becomes hard to read and fix: IFS or a lookup table with XLOOKUP are safer.

The IF function

The decision function: if the condition is true, one value; otherwise, another. Things get complicated when they are nested.

Syntax

=IF(logical_test, value_if_true, [value_if_false])

In a French Excel: =SI(test_logique; valeur_si_vrai; [valeur_si_faux]).

Arguments

logical_test: a comparison that is TRUE or FALSE, such as B2>1000.
value_if_true: what to return if it is true.
value_if_false: what to return otherwise; omitted, IF returns FALSE.

An example

=IF(AND(B2>=1000,C2="Delivered"),"Bonus","")

Returns "Bonus" if the amount reaches 1,000 and the order is delivered; an empty cell otherwise. AND requires both conditions, OR would settle for one.

Pitfalls

Text without quotes: =IF(C2=Delivered,…) returns #NAME?.
Nested IFs beyond three are hard to read: IFS or a lookup table are safer.
Comparing a number and text: "1000" as text is not greater than 999.

Going further

IFS, for several cases.
IFERROR, to replace an error.
Find the right formula: "show a result based on a condition".

Frequently asked questions

How many IFs can be nested?: Up to 64, but beyond three the formula becomes hard to read and fix: IFS or a lookup table with XLOOKUP are safer.