referencing a dynamic range of cells on another sheet

I'm trying to incorporate a range of cells (in one column) in my formula, but the amount of row cells (in that column) change given what data I'm using.

So lets say on 'Sheet1' i have a column[A] named [sample]. The amount of rows that column[A] [sample] has will change depending on what data set i am using.

On 'Sheet2' i have a formula that references all values in Column[A] on 'Sheet1'
For example =SUM(Sheet1!A2:A16)
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What can I do to change the formula so if the next data set has 20 rows in 'sheet1' [Sample] it will recognize that and include all the data?

Define a named range: I called it "Sample"

Formulas==> Define Name

Name: Sample

Refers to: =OFFSET(Sheet1!$A$2,,,COUNT(Sheet1!$A:$A),1)

in Sheet2

=SUM(Sample)

Thanks john,
That seems to have done it