Student Loan Payoff Calculator — extra payments across your loans

How it works

The simulation runs the aggregate twice. Baseline: every loan receives exactly its scheduled payment until each balance reaches zero — the do-nothing path. Accelerated: the same schedule plus your extra each month, targeted at the highest-rate loan first (CFPB's highest-interest-rate method); when a loan is retired, its scheduled payment rolls onto the remaining balances. The difference between the two runs is what the extra buys: interest never accrued and months removed from the aggregate payoff date. This page is the pure arithmetic of prepayment — income-driven repayment plans, deferment, and forgiveness are program rules, not amortization, and belong to their own calculator.

Worked example

With one loan and no extra, the simulation is a published pair: $311.38 a month on a $15,000 balance at 9% pays off in exactly 60 months (LibreTexts). On the default two-loan scenario — $20,000 at 6.5% paying $230 and $8,000 at 5% paying $90 — adding $100 a month clears everything roughly three years sooner and saves a four-figure amount of interest, this calculator's own simulation for these inputs; the exact figures on screen move with every dollar of extra and every tenth of a point of rate.

Frequently asked questions

Which loan should the extra money target?

The higher rate, if minimizing interest is the goal — each extra dollar there cancels the most expensive borrowing first, and this page's simulation applies that ordering automatically. Targeting a small balance first instead trades some interest for an earlier account closure; the debt-payoff calculator prices both orderings side by side.

Do extra payments on student loans actually reduce interest?

Yes — federal and most private student loans accrue interest on the outstanding principal, so principal removed early stops accruing for every remaining month. The saving compounds with the years remaining, which is why the same $100 saves more on a fresh loan than one nearly repaid.

What happens when one loan is paid off early?

Its scheduled payment stays in the plan and rolls onto the remaining loans — the same rollover that drives every payoff plan. That is why the aggregate finish date moves more than the first loan's size alone would suggest.

Does this model income-driven repayment or forgiveness?

No — deliberately. Those are program rules that depend on income, family size, and enrollment, not amortization arithmetic, and prepaying a loan headed for forgiveness can even be counterproductive. This page prices the pure prepayment path; check your servicer's terms before sending extra to a loan in a forgiveness track.

Should I pay extra on loans or invest the money?

That is a rate comparison — interest avoided at your loan's rate versus the uncertain return of investing — plus the program questions above. This page quantifies only the loan side; the judgment between them is yours.

Why does it say there is no payoff?

A scheduled payment at or below its loan's monthly interest never retires the balance — the loan grows or stands still. Real servicers set payments above that line, so if you see this, a payment entry is likely below the actual scheduled amount.

How accurate is this, and what does it exclude?

Exact under a monthly-accrual convention (rate ÷ 12 each month) with fixed rates and fixed scheduled payments. Federal loans actually accrue simple daily interest — balance × rate ÷ 365.25 — so real totals shift slightly from these; the student-loan calculator models that daily convention directly. It also excludes rate changes on variable private loans, capitalized interest events, servicer payment-application quirks (confirm extra goes to principal, not next month's payment), and all repayment-program rules. The comparison between the two runs, which shares every assumption, is the robust number.