About RentProrator

Empowering tenants, private landlords, and property managers across the United States with transparent, statutory-compliant rental math.

Our Mission

Rent proration is one of the most frequent sources of friction in residential real estate. Disagreements over a few days of occupancy, varying month lengths (28 vs 31 days), and obscure state notice statutes create unnecessary disputes between renters and housing providers. RentProrator.com was founded to provide an authoritative, neutral, and 100% free computational standard for all 50 US states.

Algorithmic Integrity & Precision

Every calculation executed on RentProrator utilizes exact double-precision arithmetic conforming to standard financial rounding conventions (half-up to the nearest cent). We provide transparent formulas for all four primary US proration methods:

  • Actual Calendar Days: Recommended for all residential leases.
  • Banker's 30-Day Rule: The banking and mortgage standard.
  • Annual 365-Day Rule: Standardized for institutional multifamily portfolios.
  • Commercial 360-Day Rule: Utilized in commercial and industrial leases.

Editorial & Legal Standards

Our state rental statute directory is continually reviewed against active state legislative codes, including the California Civil Code, Texas Property Code, New York Real Property Law, and the Florida Residential Landlord and Tenant Act. For questions or corrections, please contact our research team at our contact page.