401(k) Loan Repayment Calculator

Calculate your full 401(k) loan repayment schedule and understand the real cost of borrowing from your retirement savings. This calculator shows your required monthly or biweekly payment, the total interest you'll pay back to yourself, your final payoff date, and the hidden opportunity cost of missed investment growth.

This tool is for anyone considering a 401(k) loan or who already has one and wants a clear repayment plan. While a 401(k) loan can seem like an easy way to access cash, it's crucial to compare it with other options and understand the risks. For a broader view of your retirement, see how this loan impacts your long-term savings with the main 401(k) calculator. If you're considering taking money out permanently, first use the 401(k) early withdrawal penalty calculator to see the high cost of taxes and penalties.

The calculator provides a detailed amortization table showing how each payment breaks down into principal and interest. You will also see a chart illustrating your loan balance over time, a Repayment Health Score, and key insights about how the loan affects your financial future.

Start by entering your basic loan details. The Loan Amount is the total you plan to borrow. The Interest Rate is the rate set by your 401(k) plan administrator, which is often the prime rate plus 1-2%. The Repayment Term is the number of years you have to pay back the loan; most plans cap this at five years.

Next, select your Payment Frequency. Most plans deduct payments directly from your paycheck, so choose whether you are paid and make payments monthly or biweekly. This choice affects the size and timing of each payment.

To see how you can pay your loan off faster, open the Advanced settings. The Extra Monthly Payment field lets you add an additional amount to your required payment. This can significantly reduce the total interest paid and shorten your repayment timeline.

The advanced section also helps calculate the hidden costs. Enter your Current 401(k) Balance (before the loan) and the Expected 401(k) Return you might earn on your investments. These inputs allow the calculator to estimate the opportunity cost—the potential investment growth you miss out on while the money is out of your account. This is a critical part of understanding the true cost of a 401(k) loan.

Loan Amount

This is the principal amount you are borrowing from your 401(k) account. Federal rules limit 401(k) loans to the lesser of $50,000 or 50% of your vested account balance. A larger loan means a higher required payment and a greater potential opportunity cost from missed market growth.

Interest Rate

This is the annual interest rate your 401(k) plan charges for the loan. Unlike a traditional loan where interest goes to a bank, the interest you pay on a 401(k) loan goes back into your own retirement account along with the principal. The rate is typically set at the prime rate plus one or two percentage points.

Repayment Term

This is the length of time, in years, you have to repay the loan. The maximum term for a general-purpose 401(k) loan is five years. A longer term is sometimes available (10-15 years) if the loan is used to purchase a primary residence. A shorter term means higher payments but less total interest and a lower opportunity cost.

Payment Frequency

This determines how often payments are made. Most plans require repayment via payroll deduction, so this usually matches your pay schedule (monthly or biweekly). Biweekly payments can lead to paying off the loan slightly faster than monthly payments because you make 26 payments a year instead of 12.

Extra Monthly Payment

This optional input is any amount you plan to pay in addition to your required monthly payment. Making extra payments is a powerful way to reduce the total interest paid and, more importantly, get your money back into the market sooner to resume earning investment returns.

Current 401(k) Balance

This is your total vested 401(k) balance before taking the loan. This input is used to calculate your loan-to-balance ratio, which is a key factor in your Repayment Health Score. A loan that represents a large portion of your total savings is riskier and has a greater impact on your retirement readiness.

Expected 401(k) Return

This is the average annual rate of return you expect your 401(k) investments to earn. This number is used to estimate the opportunity cost of the loan—the potential growth you forfeit because the borrowed funds are not invested. A conservative estimate is often wise, as market returns are not guaranteed. This helps you compare the loan's interest rate to the potential returns you're giving up. For context, see our guide on retirement savings by age.

The calculator uses a standard amortization formula to determine your required payment based on the loan amount, interest rate, term, and payment frequency. It then builds a period-by-period schedule showing how each payment is allocated between principal and interest.

The core logic follows these steps:

1. Calculate the Required Payment: It first determines the fixed payment amount required to pay off the loan over the specified term.
2. Generate Amortization Schedule: The calculator creates a table, period by period (either monthly or biweekly). For each period, it calculates the interest accrued on the remaining balance. The rest of the payment (plus any extra payment) is applied to the principal, reducing the loan balance.
3. Calculate Opportunity Cost: In the advanced settings, the calculator projects the future value of the loan amount as if it had remained invested in your 401(k), using your expected rate of return. The difference between this projected future value and the original loan amount is the opportunity cost.
4. Determine Payoff Date: The calculator counts the total number of periods required to bring the loan balance to zero and calculates the corresponding payoff date.
5. Compute Health Score: A score is generated based on several factors: the loan-to-balance ratio (lower is better), the total interest relative to the loan amount, the length of the repayment term, and whether you are making extra payments.

The calculator does not account for the risk of job loss, which could require you to repay the entire loan balance within a short period (e.g., 60-90 days) to avoid it being treated as a taxable distribution.

The calculator uses established financial formulas to model the loan repayment.

Required Periodic Payment

The regular payment is calculated using the standard loan amortization formula.

periodic rate = annual interest rate / 100 / periods per year
total periods = repayment term in years * periods per year

regular payment = (loan amount * periodic rate * (1 + periodic rate)^total periods) / ((1 + periodic rate)^total periods - 1)

Where periods per year is 12 for monthly payments and 26 for biweekly payments.

Amortization Schedule Calculation (for each period)

For each row in the schedule, the calculations are:

interest for period = remaining balance * periodic rate
principal from payment = regular payment - interest for period
extra payment applied = min(extra per period, remaining balance - principal from payment)
total principal paid = principal from payment + extra payment applied
new balance = remaining balance - total principal paid

Opportunity Cost

This formula estimates the growth you miss by having the money out of your account.

monthly return = expected annual return / 100 / 12
loan duration in months = payoff periods / (periods per year / 12)
future value if invested = loan amount * (1 + monthly return) ^ loan duration in months
opportunity cost = future value if invested - loan amount

Borrowing from your 401(k) can be tempting, but it's a decision with significant pros and cons.

Pros of a 401(k) Loan:

• Easy to Qualify: There is no credit check, as you are borrowing your own money.
• Lower Interest Rates: The interest rate is often lower than personal loans or credit cards.
• You Pay Yourself Back: The interest you pay goes back into your own 401(k) account, not to a lender.

Cons of a 401(k) Loan:

• Opportunity Cost: This is the biggest drawback. The money you borrow is not invested, meaning you miss out on any potential market gains. If the market performs well, this lost growth can cost you far more than the interest you pay.
• Repayment on Job Separation: If you leave your job (voluntarily or not), you typically must repay the entire outstanding loan balance within a short window, often by the tax filing deadline for that year. If you can't, the balance is treated as a taxable distribution, and you may owe a 10% early withdrawal penalty if you're under 59½.
• Double Taxation: You repay the loan with after-tax dollars. When you withdraw that same money in retirement, it will be taxed again as ordinary income.
• Reduced Contributions: Some people pause their regular 401(k) contributions while repaying a loan, which slows their long-term savings progress and means they miss out on a potential employer match.

Before taking a loan, consider alternatives like a home equity line of credit (HELOC), a personal loan, or a 0% APR credit card offer, especially for short-term needs. A 401(k) loan should primarily be reserved for true emergencies after other options have been exhausted.

The IRS sets specific rules for 401(k) loans that all plans must follow.

• Maximum Loan Amount: You can borrow up to 50% of your vested account balance, but no more than $50,000. If your vested balance is less than $20,000, you may be able to borrow up to $10,000, even if it's more than 50% of your balance.
• Repayment Term: For a general-purpose loan, the maximum repayment period is five years.
• Home Purchase Exception: The five-year rule can be extended (often to 15 years) if the loan is used for the purchase of a primary residence.
• Level Payments: Repayments must be made in substantially level payments (amortized) at least quarterly, but most plans require more frequent payments via payroll deduction.
• Interest Rate: The interest rate must be "reasonable," which is typically interpreted as the prime rate plus one or two percent.

It's important to check your specific plan's summary plan description (SPD), as some plans may have more restrictive rules than the IRS minimums. For example, a plan might not allow loans at all, or it may limit you to one outstanding loan at a time.

A 401(k) loan is not the same as a hardship withdrawal. Understanding the difference is crucial.

A hardship withdrawal should be a last resort. It permanently depletes your retirement savings and triggers immediate taxes and penalties. A loan, while risky, at least preserves the principal in your account if repaid successfully. Before considering a withdrawal, use the 401(k) withdrawal calculator to see the full tax impact.

• Repayment Health Score: This gives you a quick assessment of your loan's impact. A high score (80+) suggests a manageable loan. A low score (<50) indicates the loan is large relative to your balance or has a high interest cost, posing a greater risk to your retirement.
• Monthly/Biweekly Payment: This is the required amount that will be deducted from your paychecks to repay the loan on schedule.
• Total Interest: This is the total amount of interest you will pay over the life of the loan. Remember, this interest goes back into your own account.
• Payoff Date: The date your loan balance will reach zero based on your payment schedule.
• Opportunity Cost: This is the most important result. It estimates the potential investment growth you lose because the borrowed money isn't in the market. This is the true, hidden cost of a 401(k) loan.
• Loan Balance Over Time Chart: This visual shows how your loan principal decreases with each payment you make.
• Amortization Schedule: This table provides a detailed breakdown of every single payment, showing how much goes toward principal versus interest and the remaining balance after each payment.

If you're concerned about the impact of a 401(k) loan, here are actionable steps to minimize the damage:

1. Make Extra Payments: Even a small extra amount each month can shorten the loan term, reduce opportunity cost, and get your money back to work for you sooner.
2. Use Biweekly Payments: If your plan allows and you are paid biweekly, this schedule results in 26 payments per year, equivalent to 13 monthly payments, which accelerates your payoff.
3. Continue Contributions: Do not stop contributing to your 401(k) while repaying the loan. At a minimum, contribute enough to get your full employer match. Stopping contributions means you lose out on "free money" and fall further behind on your retirement savings goals.
4. Borrow the Minimum Necessary: Only borrow what you absolutely need. The smaller the loan, the smaller the payments and the lower the opportunity cost.
5. Build an Emergency Fund: The best way to deal with a 401(k) loan is to avoid needing one in the first place. Prioritize building an emergency fund with 3-6 months of living expenses in a high-yield savings account.

1. Ignoring Opportunity Cost: Focusing only on the interest rate and forgetting about the lost market growth is the biggest mistake. A 5% loan interest rate seems cheap until the market returns 15% that year.
2. Not Having a Plan for Job Loss: Many people are caught off guard by the requirement to repay the loan in full if they leave their employer. This can turn a manageable loan into a major tax bill.
3. Pausing 401(k) Contributions: Stopping contributions to make loan payments is a double loss—you lose your new savings and any employer match.
4. Using it for Lifestyle Spending: Taking a loan for a vacation, car, or other non-essential purchase is a poor use of retirement funds and can create bad financial habits.