How student loan amortization works

What “standard amortization” means here

For a fixed-rate amortizing loan, each month’s payment is set so principal and interest clear over a chosen term. Early payments are interest-heavy; later payments retire more principal — when the rate is positive.

This site’s student loan tool estimates that standard path from balance, rate, and term you enter. It is an educational estimate — not official federal or servicer tooling.

Use the student loan calculator. For multiple debts with snowball or avalanche ordering, open the debt payoff calculator.

The standard payment

Monthly rate r = annual rate ÷ 100 ÷ 12. For n months and principal P:

M = P × r × (1 + r)^n / ((1 + r)^n − 1)

If the rate is 0%, M = P / n. The amortization schedule uses the same engine as the payment.

Optional higher fixed payment

If you enter an optional monthly payment greater than the standard amortizing payment, the tool can simulate an accelerated fixed-payment payoff under the same monthly interest rules. That scenario is labeled an accelerated path — not a federal repayment plan.

Assumptions (MVP)

• Supported plan: standard — fixed-rate amortizing loan over the entered term
• Fixed nominal annual rate converted to a monthly rate ÷ 12
• No fees, deferment, forbearance, or refinancing modeled
• Unsupported plan names error clearly (no silent fallback)

Limitations

• Does not implement IDR, forgiveness, capitalization, subsidies, or eligibility rules
• Results are based on the assumptions entered — not a claim that one plan is better for you

Takeaways

Student loan amortization in this MVP is standard fixed-rate math plus an optional faster fixed payment. Program-specific federal rules stay out until they are fully specified and sourced.