Calculator
What's it worth?
Enquiries a month, how many become jobs, and what a job is worth. Then an estimate of more enquiries from the same traffic. The difference is arithmetic from your numbers, not a promise.
What's it worth?
Three figures you already know. The slider estimates more enquiries from the same traffic. It starts at a cautious 10%. That is an estimate, not a promise, and it is not an industry average.
If the model is useful, the next step is a website check or starting a project.