Per-Diem Prorated Interest at Closing
Daily interest and prepaid interest from closing through end of month for the CFPB Closing Disclosure.
Example
You enter
- Loan amount ($) 300000
- Annual interest rate (percent) 6
- Closing date (YYYY-MM-DD) 2026-06-15
- Day-count convention actual365
You get
- Daily interest 49.3151
- Days to end of month 16
- Prepaid interest at closing $789.04
Checked against published worked examples from: CFPB Closing Disclosure (12 CFR 1026.38, Appendix H).
Details, formula, and sources
ScopeActual/365, Actual/360, or 30/360.
Formula or tabledaily_interest = loan_amount * (annual_rate/100) / basis (365, 360, or 30/360). days_to_eom = last_day_of_month - closing_day + 1 (counting the closing day; 30/360 uses 30 - min(closing_day, 30) + 1, so a close on the 31st accrues one day). prepaid_interest = daily_interest * days_to_eom.
Source and editionCFPB Closing Disclosure (12 CFR 1026.38, Appendix H) prepaid-interest line item.
Free accessClosing Disclosure form and Regulation Z free at consumerfinance.gov and ecfr.gov.
What governsEstimate. Lender governs final underwriting and rate / fee disclosure. Appraiser governs the appraised value. State law and the agency's program guidelines may impose stricter limits than the published thresholds.
API field namesloan_amount, annual_rate_pct, closing_date_iso, day_count, daily_interest, days_to_eom, prepaid_interest
- Stub period closing day through the last day of the closing month, inclusivestandard prepaid-interest convention
- Day-count basis 365, 360, or 30/360 per the selected conventionlender disclosure