Hi there and welcome to the Community, @Stephen_Henry 
Glad to say that you can let users submit the contact info using the built-in form feature! To enable it, choose Open Form as the Button Action in the Results section:
Once this done, you can set up the form using the Edit Form button. Check this post for more details - Calculator: Send calculation results directly to email + Integrations! 🚀.
The good news is that you can not only receive form submissions with results and contact info, but automatically send them to emails of your clients. For this, you should open the Email Notifications in the Edit Form section, choose Notify Respondents and enable Autoresponder:
This way, your clients won’t have to download the results, as they’ll be delivered to their emails right away.
However, if you’d still prefer to send the form submissions to your Hubspot workspace, you can use the Zapier integration, where Hubspot is also available:
Please let me know if it worked for your needs or if you have any questions left 