401(k) Loan Calculator
Calculate 401(k) loan repayment, interest paid back to yourself, and the opportunity cost of lost market returns. See the true cost of borrowing from retirement.
Loan Balance Calculator
Calculate remaining loan balance at any point in time. See equity progress, payoff acceleration with extra payments, and payment history breakdown.
$
%
years
years
$
Current Balance⧉
$280,833.00
After 5 years of payments
Monthly Payment⧉
$1,896.20
Original schedule
Principal Repaid⧉
$19,167.00
6.4% of original loan
Interest Paid⧉
$94,605.00
Interest paid to date
Remaining Interest⧉
$288,028.00
If no extra payments
Adjusted Balance⧉
$280,833.00
No extra payment
Equity Progress
6.4% paid
Payoff Acceleration
| Extra/Month | Months Left | Years Left | Remaining Interest |
|---|---|---|---|
| Standard | 300 | 25 | $288,028.00 |
| +$100.00 | 266 | 22.2 | $249,674.00 |
| +$250.00 | 229 | 19.1 | $209,296.00 |
| +$500.00 | 187 | 15.6 | $166,019.00 |
| +$1,000.00 | 138 | 11.5 | $118,547.00 |
Payoff Milestones
| % Paid Off | Year | Remaining Balance |
|---|---|---|
| 25% | 14 | $225,987.00 |
| 50% | 21.3 | $150,468.00 |
| 75% | 26.3 | $75,545.00 |
| 90% | 28.6 | $30,716.00 |
Payment History
| Year | Principal | Interest | Balance |
|---|---|---|---|
| 1 | $3,353.00 | $19,401.00 | $296,647.00 |
| 2 | $3,578.00 | $19,177.00 | $293,069.00 |
| 3 | $3,817.00 | $18,937.00 | $289,252.00 |
| 4 | $4,073.00 | $18,681.00 | $285,179.00 |
| 5 | $4,346.00 | $18,409.00 | $280,833.00 |
Planning notes, formulas, and examples
About the Loan Balance Calculator
Knowing your exact remaining loan balance is essential for financial planning — whether you are considering refinancing, making a lump-sum payment, selling a property, or simply tracking your progress toward being debt-free. The remaining balance depends on the original terms, interest rate, and how many payments you have made.
Due to amortization, the balance does not decline linearly. In the early years, most of each payment goes to interest, so the principal drops slowly. This means that after 10 years of a 30-year mortgage, you may have only paid off 15-20% of the principal despite making a third of the total payments.
This calculator shows your current balance at any point in the loan, the split between principal and interest paid to date, an equity progress bar, payoff acceleration scenarios showing how extra monthly payments can shorten your remaining term, and the key milestones — when you will reach 25%, 50%, 75%, and 90% paid off.
When This Page Helps
Loan statements show your current balance, but they do not show the whole amortization picture — how much of your payments went to interest vs principal, how far along you are, and how extra payments can change your payoff date. This calculator adds the payoff context you need before refinancing, prepaying, or selling.
How to Use the Inputs
- Enter the original loan amount when it was taken out.
- Input the interest rate on the loan.
- Set the original loan term in years.
- Enter how many years have elapsed since origination.
- Optionally add a lump-sum extra payment to see the adjusted balance.
- Review remaining balance, equity progress, and payoff scenarios.
- Use the payoff acceleration table to plan extra payments.
Formula used
Balance after k payments: B(k) = P × [(1+r)^n − (1+r)^k] / [(1+r)^n − 1], where P = original principal, r = periodic rate, n = total periods, k = periods elapsed.Example Calculation
Result: Current balance: $281,870 — Principal paid: $18,130 — Interest paid: $95,210 — Equity: 6%
After 5 years of a $300K mortgage at 6.5%, only $18,130 of principal has been repaid — just 6% equity from payments. Meanwhile, $95,210 has gone to interest. Adding $250/month extra from this point would pay off the loan 9 years sooner and save $113K in interest.
Tips & Best Practices
- In the first 5-10 years, over 70% of each payment typically goes to interest — balance drops slowly.
- Making extra payments toward principal in early years saves the most interest over the loan life.
- Check your balance before refinancing — the remaining term and balance determine if it makes sense.
- A lump-sum prepayment (bonus, inheritance) has enormous impact early in the loan.
- The 50% payoff milestone on a 30-year loan typically occurs around year 20-22, not year 15.
- Use the payoff acceleration table to find the sweet spot between extra payments and lifestyle.
Balance Progress
Amortization front-loads interest, so the balance falls slowly at first and faster later. That is why a loan can feel barely reduced even after years of payments.
Extra Payments
Use the extra-payment scenario to see how much principal you can knock off immediately. Early prepayments usually save the most interest because they act on the largest remaining balance.
Planning Ahead
Check the remaining balance before refinancing, selling, or making a lump sum payment so the decision is based on the actual payoff position rather than a rough estimate.
Sources & Methodology
Last updated:
Methodology
This page calculates the scheduled payment from the original principal, rate, and term, then walks through the amortization schedule month by month until the entered elapsed time to estimate remaining balance, principal repaid, and interest paid. It also applies an optional lump-sum reduction, projects remaining interest if the schedule continues unchanged, and shows payoff acceleration scenarios for extra monthly payments from the current balance forward.
The output assumes a fixed rate and regular on-time payments. Escrow, late charges, rate resets, missed payments, deferments, and servicer-specific daily-interest conventions are outside scope, so the page should be used as a payoff-position worksheet rather than as a substitute for the official payoff statement.
Sources
- What is amortization and how could it affect my auto loan? (Consumer Financial Protection Bureau) — CFPB explanation of how amortization shifts payments from mostly interest to mostly principal over time.
- How do mortgage lenders calculate monthly payments? (Consumer Financial Protection Bureau) — CFPB reference for the fixed-payment loan formula used to reconstruct the amortization path.
Frequently Asked Questions
This is the nature of amortization. In the early years, the interest portion of each payment is very high because the balance is large. On a 30-year mortgage at 6.5%, only about 20% of the first payment goes to principal. As the balance decreases, the principal portion grows, and the balance declines faster in later years.
Loan equity from payments = Original loan − Current balance. If you also bought with a down payment, total home equity = Home value − Current loan balance. This calculator shows equity from payments. Actual equity also reflects any home value appreciation or depreciation.
A lump sum reduces the balance immediately, saving more interest than the same amount spread over months. However, monthly extra payments provide discipline and steady progress. Ideally, apply lump sums when available (bonuses, tax refunds) and also maintain regular extra payments.
This calculator uses the standard amortization formula and assumes regular on-time payments with no missed payments or late fees. Your actual balance may differ slightly due to rounding, payment timing, escrow adjustments, or rate changes (for variable-rate loans).
Refinancing makes sense if you can lower the rate by 0.75%+ and plan to stay long enough to recoup closing costs (break-even typically 2-4 years). Prepaying makes sense when rates are already low and you want to reduce the term without refinancing costs. Compare both scenarios.
Maximize extra payments — every dollar above the minimum goes directly to principal. Bi-weekly payments (26 half-payments = 13 full payments/year) add one extra payment annually. Even rounding up to the nearest $100 helps. The payoff acceleration table shows the impact of various extra payment amounts.
More in this topic
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