sub lastrow()
lastrow = Range("A" & Rows.Count).End(xlUp).Row
Msgbox lastrow
End sub


*************************************
Other ways
**************************************

Sub FindingLastRow()

'PURPOSE: Different ways to find the last row number of a range

Dim sht As Worksheet
Dim LastRow As Long

Set sht = ThisWorkbook.Worksheets("Sheet1")

'Ctrl + Shift + End
LastRow = sht.Cells(sht.Rows.Count, "A").End(xlUp).Row

'Using UsedRange
sht.UsedRange 'Refresh UsedRange
LastRow = sht.UsedRange.Rows(sht.UsedRange.Rows.Count).Row

'Using Table Range
LastRow = sht.ListObjects("Table1").Range.Rows.Count

'Using Named Range
LastRow = sht.Range("MyNamedRange").Rows.Count

'Ctrl + Shift + Down (Range should be first cell in data set)
LastRow = sht.Range("A1").CurrentRegion.Rows.Count

End Sub