The HubSpot CRM includes 15 minutes of HubSpot Calling for free.
HubSpot Sales Professional includes 2,000 minutes of HubSpot Calling per month, plus more as needed. HubSpot Sales Pro includes other sales productivity tools, in addition to HubSpot Calling. See everything that's included in the full version of HubSpot Sales Pro here. If you'd like to upgrade, click here for more information.
You can find information on the service limits in each of HubSpot's products here.