Capacity is the present value of payments you can actually afford.
Given a fixed payment budget, rate and repayment term, the maximum fully amortizing principal is the present value of those payments. This is a financing identity; the payment budget is supplied by the user and must already reflect other debt, reinvestment and cash buffers.
A longer amortization supports more principal for the same payment but increases the time exposed to operating and rate assumptions. This model does not set leverage limits, collateral requirements, covenant headroom or lender eligibility.
The formula, made clear.
- Available payment
- Cash reserved for a single proposed debt obligation in each selected payment period.
- Capacity
- Principal whose equal amortizing payments match the budget before any fees.
Put the numbers in context.
$100.00 available monthly for 12 payments at 0% supports $1,200.00 principal. At a positive rate, part of each payment funds interest and the supported principal is lower.
| Input | Example value |
|---|---|
| Available payment each period | $30,000.00 |
| Nominal annual interest rate | 12% |
| Payments per year | Monthly |
| Amortizing payment count | 36 payments |
| Fully amortizing principal capacity | $903,225.15 |
What this calculation assumes
Constant payment budget, fixed nominal rate, equal period-end payments, no initial interest-only phase, balloon, fees, prepayments or draw delays. Capacity is gross principal before financing charges. It is not an estimate of lender underwriting, creditworthiness or approval.
Methodology references
What to consider next.
Use the supported principal in the debt schedule and add actual fees. Stress-test the payment budget against operating cash and existing debt obligations.
How we approach financial models →