I built out this quick interactive tool where you can input the following parameters and see how it impacts MRR/ARR over 24 months.
Average MRR
Website Visitors
Free Trial Conversion Rate
Paid Signup Conversion Rate
Churn Rate
https://grid.is/@davecarruthers/saas-calculator-RxAMhU3iSjibty9LdnfYpw
Hope its helpful, let me know if you have any ideas for improvements.
The platform I used to build it is actually really cool, allows you to connect up a Google Sheet with all the underlying logic and then set fields as inputs or outputs.