The Spiffing Brit did a video on YT Premium revenue [0]. My understanding is all the money from all the premium subscribers is thrown into a big pool, of which YouTube takes 45% (or whatever their share is) right off the bat. Then, they take each Premium subscribers’ total watch time across all the channels they watched videos on, and split the remaining money based off of total premium subscriber watch time to each channel.

For example, imagine there are only three YouTube channels out there, The Spiffing Brit, Pewdiepie, and MrBeast. There’s $1,000,000 USD remaining in the pot for the month (or pay period, I’m not sure how regular the payouts are) after YouTube takes their cut. In sum total, YT Premium subscribers watched 100,000 minutes of content: 50,000 minutes to MrBeast, 40,000 minutes to Pewdiepie, and 10,000 minutes to The Spiffing Brit. The payouts would be calculated using:

revenue_share_ratio = sum_channel_premium_watch_time / sum_global_premium_watch_time

channel_premium_payout = global_premium_payout * revenue_share_ratio

So:

MrBeast: revenue_share_ratio = 0.50 = 50,000 / 100,000 channel_premium_payout = 500,000 = 0.50 * 1,000,000

Pewdiepie: revenue_share_ratio = 0.40 = 40,000 / 100,000 channel_premium_payout = 400,000 = 0.40 * 1,000,000

The spiffing brit: revenue_share_ratio = 0.10 = 10,000 / 100,000 channel_premium_payout = 100,000 = 0.10 * 1,000,000

A bit of a contrived and simplified explanation I’m sure, but as far as I am aware the formulae they use to divvy up the money between creators is as straight forward as it gets. Money out per creator = global money in total * (creator minutes total / global minutes total)

[0]: https://youtu.be/NLO5-IyS5pE