SOS! Need help with my customer LTV figures to respond to a potential investor

Hey everyone

This one is a doozy. So I'm in very early talks with a pre-seed investor and they are challenging me on our ability to scale due to disproportionately high customer acquisition costs relative to projected customer lifetime value (LTV). I just need someone to take a look and let me know if my LTV calculation method will get me laughed at.

So my base method is: monthly revenue per customer x gross margin / monthly churn rate percentage = LTV. So for example $100 monthly customer revenue multiplied by 85% gross margin = $85, divided by 0.83% monthly churn (10% annual churn divided by 12 month ) = $10,240 LTV.

I know there are a few brave souls that will wade into these waters to help out a fellow IH. Are these calculations correct? Is this a valid method for figuring LTV?

Thanks a million
Cole