INDEX...retrun the closesed value

[Helmut0806]

I try to have returned the value coming most closeley to the value in the matrix:

Specifically, I try to define an insulation thickness of the pipe, depending on diameter and operating temperature :

How can I define the formular so that a thickness is defined, if the operating value does not exactly match any of the values of the matrix, but is between two of them?

example: if Ø508 and Temp. 380, the vlaue to be returned should be 180

Thank you!

helmut

[#2 · Accepted solution]

@Helmut0806 

=INDEX($C$2:$I$11,MATCH(B15,$B$2:$B$11,0),MATCH(B16,$C$1:$I$1,-1))

Maybe with this formula as shown in the attached file.

[#3]

thank you! :)

[#4]

Hi@Helmut0806 ,

If you order the values in ascending order, I can think of a solution in two steps: list intermediate values, and search them with HLOOKUP.

Kind regards

Hans

[#5]

Dankeschön!
First solution helped already; it was the "-1" missing ;)

[#6]

@Helmut0806 

-1 returns next smaller item, not the closest one. If you are 365 or 2021 that could be like

=XLOOKUP( 0, ABS( $B$17 - $B$3:$B$14),  XLOOKUP(0,ABS(B16-$C$2:$L$2),$C$3:$L$14,,1),,1 )

for

or its equivalent for previous Excel versions.