Borrowing capacity (addon)

Estimate principal from addon rate, payment count, and monthly payment amount.

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Calculation specification

Reviewed on:

Formula basis

Principal P=(monthly payment×m)/{1+a×m/12}. Total payment is monthly payment×m, and interest is total payment minus rounded principal.

Calculation method

Solves the principal affordable from an addon rate, number of months, and fixed monthly payment.

Exclusions and checks required

  • This algebraic result does not incorporate credit underwriting or product limits.
  • Fees, payment-date differences, prepayment, and final-payment adjustment are excluded.

Example input:：JPY 30,000 for 36 months at a 6% addon rate

annualAddonRate
6
months
36
monthlyPayment
30000
rounding
floor

The displayed principal reflects the selected whole-yen rounding and is not a loan offer.

FAQ

Who is this calculator for? Borrowing capacity (addon)

Estimate principal from addon rate, payment count, and monthly payment amount.

What values should I enter?

Applies to: Addon loans / Borrowing capacity = monthly payment × periods / (1 + annual addon rate × periods / 12)

How should I interpret this estimate?

Solves the principal affordable from an addon rate, number of months, and fixed monthly payment.

How to use

  1. Enter your input values and press Calculate.
  2. Review the result and compare it with expected context.
  3. Principal P=(monthly payment×m)/{1+a×m/12}. Total payment is monthly payment×m, and interest is total payment minus rounded principal.