Hi Grant Pestka,

Lead Conversion Mapping
 
When you convert a lead, the standard lead fields are automatically converted to the account, contact, and opportunity fields listed below. Custom lead fields are converted to custom account, contact, and opportunity fields as specified by your administrator (see Mapping Custom Lead Fields).
Lead FieldMaps toAddressAccount: Billing Address
Contact: Mailing Address
Annual RevenueAccount: Annual Revenue
CampaignOpportunity: Primary Campaign Source
If the lead has multiple associated campaigns, the most recently associated campaign is inserted into the opportunity regardless of whether the user has sharing access to it.
CompanyAccount: Account Name
Contact: Account
Opportunity: Account Name
Opportunity: Opportunity Name
Company Name (Local)Account: Account Name (Local)
DescriptionContact: Description
Do Not CallContact: Do Not Call
This field is not updated for leads converted to existing contacts.
EmailContact: Email
Email Opt OutContact: Email Opt Out
This field is not updated for leads converted to existing contacts.
FaxAccount: Fax
Contact: Fax
Fax Opt OutContact: Fax Opt Out
First NameContact: First Name
First Name (Local)Contact: First Name (Local)
IndustryAccount: Industry
Last NameContact: Last Name
Last Name (Local)Contact: Last Name (Local)
Lead OwnerAccount: Owner
Contact: Owner
Opportunity: Owner
Lead SourceContact: Lead Source
Opportunity: Lead Source
MobileContact: Mobile
No. of EmployeesAccount: Employees
Partner AccountOpportunity: Partner Account
This field is not updated for leads converted to existing opportunities.
PhoneAccount: Phone
Contact: Phone
RatingAccount: Rating
TitleContact: Title
WebsiteAccount: Website

Hope this information helps you!

If this helps you please mark it as solved.

Thanks and Regards
Sandhya