Why does an Excel spreadsheet end at 1048576 and XFD?

Question

Hello,

Why does an Excel spreadsheet end at 1048576 and XFD?

Rows and columns. Can't go any further.

Answer 1

Excel 2007 and above supports 2^14 columns, i.e. 16384 columns. They are labeled with the 26 letters of the alphabet, so the labeling is a 26 base system, not a 10 base system like our numbers. 

In our 10 based numbering system we have the digits 0 to 9. We start numbering with 1 and the next number after 9 uses another digit and starts that digit at 0. Hence 1, 10, 100. (Strictly speaking, our numbering system should start with a 0 instead of a 1, but that's a different story).

In Excel, columns are numbered with a system that has 26 digits instead of 10. 

The first 26 columns are A to Z. The 27th column uses another digit and starts that digit at A, hence AA.

column 26 = Z

column 27 = AA

column 28 = AB

column 29 = AC

...

column 52 = AZ

column 53 = BA

column 54 = BB

...

When all the two-digit headers have been used, another digit is added.

column 702 = ZZ

column 703 = AAA

column 704 = AAB

... 

... and finally

column 16384 = XFD

In a 26 base system, the value XFD equals 16384.

Excel 2007 and above supports 2^20 rows, i.e. 1048576 rows. They are just numbered from 1 to 1048576.

Answer 2

Re:  spreadsheet size

In xl2003 and earlier versions there are 65536 rows x 256 columns or approximately 16 Million cells.

In Excel 2013 there are ~17 Billion cells;  how many do you need?

'---

Jim Cone

Portland, Oregon USA

Answer 3

2*2*.... 14 times will give you the limit i.e. 16384

XFD is reflecting the last number of column 16384.

1	2	2
2	2	4
3	2	8
4	2	16
5	2	32
6	2	64
7	2	128
8	2	256
9	2	512
10	2	1024
11	2	2048
12	2	4096
13	2	8192
14	2	16384
15	2	32768
16	2	65536
17	2	131072
18	2	262144
19	2	524288
20	2	1048576

Answer 4

I was thinking about this briefly, and then I looked for and found this page.

It occurred to me, why didn't they go to 2^16?  That would allow for 65536 columns.  Sure, but then after XFD, you would have to go to XFE, etc.  No problem, right?  But eventually, it won't be too long until you reach ZZZ--long before you get to the 15th bit.  (I don't feel like claculating what number that would be--but it wouldn't be difficult.)  So then what will you have to do?  You'd have to go to AAAA.  What a pain.  Then people will start complaining about not going until you get to ZZZZ.  But you'll never get a perfect confluence between powers of 2 (bits) and powers of Z (letters).  You gotta draw the line somewhere.  I think XFD is enough.

Answer 5

Just a little additionnal comment :

If we want to calculate the equivalent of column numbers XFD in 26 base, we should do like this :

X is the 24th letter of the alphabet so we have 26 x 26 x 24

• F is the 6th letter of the alphabet so we have 26 x 6
• D is the 4th letter so we have 4

The grand total is : 26 x 26 x 24 +26 x 6 + 4 = 16 384

Best regards.

Chris