We don’t “know” because they haven’t released any numbers but the most optimistic estimates (which many people believe are very very optimistic) put it at 60%: https://newsletter.semianalysis.com/p/anthropic-growth-and-b...

The simple question to ask is, if it is so profitable, where is all the money going? If Anthropic have 90% margins on API usage and API usage is $50bn+ in revenue per year, where is the $45bn going? Why do they need to raise so much cash, constantly?