A1 Notation Range Builder

Convert column numbers to letters and back, and build the A1 range to give a scheduled job — including the open-ended form that does not truncate.

Column number → letter

Letter: AA

Column letter → number

Number: 27

Build a range

Sheet1!A2:D

Ready to automate?

Simple Data Foundry reads and writes any A1 range on a schedule — append below what is there, or overwrite the range outright.

Frequently Asked Questions

How do column letters work past Z?

They are bijective base-26, which is not quite the same as normal base-26. After Z comes AA, not BA, because there is no zero digit — A is 1, Z is 26, AA is 27. That off-by-one is why naive conversions break at exactly column 26 and again at 702.

What is an open-ended range?

A range with no end row, like Sheet1!A2:D. It means "from row 2 down, columns A to D, however far the data goes". Compare A2:D1000, which fixes an arbitrary boundary you have to remember to raise.

Why does that matter for a scheduled sync?

Because a padded range lies to the tool reading it. A2:D1000 claims a thousand rows exist, so reads come back padded with empty rows and appends have an ambiguous boundary. When the data eventually exceeds row 1000 it is silently truncated — and nothing errors, which is the worst kind of failure.

Do I need to quote the sheet name?

Only when it contains a space or a character that would otherwise be parsed, in which case it needs single quotes: 'Q3 Report'!A1:D. The builder adds them when required, and an apostrophe inside the name is escaped by doubling it.

Are there limits I should know about?

A Google spreadsheet caps at 10 million cells across every tab, and a single sheet at 18,278 columns — column ZZZ. Both are easier to hit than people expect when a job writes a wide table on a schedule, which is the argument for selecting columns before you write rather than after.