Not a calculation but there are some tables in this article that give you an idea of what utxo size would be appropriate at different potential fee rates. It shows you at different fee rates what percentage of the utxo would be spent in fees given different utxo sizes.

How to prevent small UTXOs from becoming bitcoin dust - Unchained

That's cool, mate! Will give a read. When I think about this, fees are just part of the equation. The how much you can buy and how much change you'll get count. How often do you do consolidations. What's the security threat model and so on.

Even the question of what entity you are. An individual? A business? Are you acting in the interest of others, like family?

So much to consider! 🤯 You are right to point out it is a lot more than just how much is eaten up by potential fees.