How many years old is the oldest known writing?

How to get close to this number

Anchor on the civilisations you can date. The first cities and states appear around five to six thousand years ago, and writing emerged as an administrative tool of those states rather than before them. The answer has to sit just inside the start of urban civilisation.

The content of the earliest tablets is the genuinely revealing part: not poetry or law but accounting — records of grain and beer rations. Writing was invented to track inventory, and literature came later. A technology that now defines culture began as a solution to a warehouse problem.

That order of invention keeps recurring. Numbers predate letters, contracts predate stories, and the pressure that produces a new medium is almost always administrative rather than expressive. The oldest surviving human texts are receipts, which is a better summary of what writing is for than any account of its literary uses.