Amortization Schedule Builder

Deterministic amortization schedule builder covering level-payment, ARM (index plus margin, periodic and lifetime caps, recast), interest-only, balloon, and temporary buydown (2-1 or 3-2-1) structures, per the unit-period and odd-days conventions in 12 CFR 1026 Appendix J. Returns the full period-by-period schedule (principal, interest, ending balance), totals, a schedule_digest, and advances/payments arrays shaped for direct use as the actuarial APR solver's input. Cents-integer fixed-point math throughout; no floating-point drift.

Tool URL: https://ainumbers.co/chaingraph/art-332-build-amortization-schedule.html