Estimation Builder is web-based estimating and invoicing software for construction professionals, including general contractors, remodelers, landscapers, concrete crews, and specialty trades. Users build itemized estimates with line items priced by square foot, cubic foot, linear foot, hourly rate, quantity, or flat rate. Each estimate generates a branded PDF proposal that can be emailed to the customer and signed online, and accepted estimates convert to invoices in one click with support for partial payments and balance tracking per job. The application also includes customer and job records, reusable estimate templates for repeat work, change orders against signed estimates, a catalog of saved line items, configurable acceptance deadlines and down-payment terms, and Stripe-based subscription billing for the contractor's account. Estimation Builder is delivered as a hosted SaaS application with no desktop install, priced as a flat monthly subscription per company that includes unlimited estimates, invoices, and customers.