Home Equity Loan vs. 401(k) Loan: Key Differences

This calculator estimates the monthly payment and total interest for a fixed-rate, fully amortizing loan; enter the amount, APR, and term to see the results. It models standard loan payments, not the separate risks or account rules that apply to home equity loans and 401(k) borrowing.

Formula

The calculator uses the standard fixed-payment amortization formula. Let P be the loan principal in dollars, a the annual percentage rate (APR) in percent, r = a / 1200 the monthly rate as a decimal, and n = 12 × years the number of monthly payments. Monthly payment is P × r / [1 − (1 + r)⁻ⁿ]. Total interest is the monthly payment multiplied by the number of payments, minus the original principal. Outputs are rounded to cents by display; actual lender calculations can differ.

Worked Example

Using the defaults: principal P = $20,000, APR a = 8%, and term 5 years.

• Monthly rate: r = 8 / 1200 = 0.0066667.
• Number of payments: n = 5 × 12 = 60.
• Payment: $20,000 × 0.0066667 / [1 − (1.0066667)⁻⁶⁰] ≈ $405.53.
• Total interest using the displayed payment: $405.53 × 60 − $20,000 = $4,331.80.

Assumptions

• The APR and payment remain fixed for the full term.
• Payments are made monthly, at the end of each period.
• Interest compounds monthly at APR / 12.
• Fees, taxes, insurance, account charges, and any tax effects are not included.

How Home Equity and 401(k) Borrowing Work

A home equity loan is generally a loan secured by the equity in a home. The borrower receives a lump sum and repays it under the lender’s terms. Because the home secures the debt, failing to repay can put the home at risk. A home equity loan is different from a home equity line of credit, which typically allows borrowing and repayment over a revolving draw period.

A 401(k) loan is a loan from a workplace retirement plan, if the plan permits borrowing. The plan sets the available terms and process. Repayment is generally made through payroll deductions, with interest credited to the participant’s account under plan rules. It is not a loan secured by the home, but borrowing reduces the amount invested in the account while the balance is outstanding. The plan document or administrator is the source for the actual rules.

Neither arrangement is simply “borrowing your own money.” A 401(k) loan creates a repayment obligation and may affect investment growth; a home equity loan creates debt secured by property. Specific terms, tax treatment, and consequences depend on the loan and applicable rules, so verify details with the plan administrator and lender or a qualified tax professional.

Comparing Costs and Risks

The calculator gives an apples-to-apples estimate only when the two options’ principal, APR, and term are entered. Real comparisons should also account for costs and consequences the formula cannot capture:

• Up-front and ongoing charges: A home equity product may include lender fees or other charges. Ask for the written fee schedule and disclosures; do not infer costs from the APR alone.
• Collateral: Nonpayment on a home-secured loan can threaten the property. A 401(k) loan does not put the home up as collateral, but a missed or disrupted repayment can have plan-specific consequences.
• Retirement impact: Money borrowed from a retirement account is not invested in the same way while out of the account. The future effect depends on market returns, repayment, and the investment choices available.
• Job changes: Leaving an employer can affect how and when a plan loan must be repaid, and what happens if it is not. Confirm the terms before borrowing rather than assuming payroll deductions continue unchanged.
• Repayment flexibility: Compare payment frequency, term, prepayment provisions, and what happens after a missed payment. These details are not represented by a basic amortization estimate.

For example, entering $20,000 at 8% for five years produces an estimated payment of $405.53 and total interest of $4,331.80 under this formula. That calculation does not establish that either borrowing option actually offers those terms, include fees, or measure the opportunity cost of retirement investments.

How to Make a Useful Comparison

1. Ask for the actual proposed amount, APR, term, payment schedule, and all fees for the home equity loan.
2. Ask the retirement plan administrator whether loans are available and request the plan’s interest, repayment, job-separation, and default terms.
3. Enter each option’s principal, APR, and term into the calculator separately. Use the same borrowing amount where possible.
4. Compare estimated payments and interest, then consider collateral, retirement-account effects, fees, repayment reliability, and consequences not included in the formula.

Do not treat a 401(k) loan’s interest paid into the account as a cost-free return: the borrowed money is also out of the market, and the result depends on investment performance and plan terms. Likewise, a lower payment alone does not show a lower total cost; a longer term can reduce the monthly amount while increasing total interest.

Alternatives and Common Misconceptions

Depending on the purpose and circumstances, other possibilities may include saving toward the expense, negotiating a payment schedule with the provider, or comparing an unsecured personal loan. Each has its own cost, qualification process, and risks; this calculator does not evaluate those options. A home equity line of credit is another home-secured form of borrowing, but its variable balance and payment structure may not fit this fixed-payment formula.

A common misconception is that a 401(k) loan is harmless because repayments go back into the account. Repayment does restore principal and interest under the plan’s terms, but it does not erase the investment exposure while the money is borrowed or the consequences of failing to meet plan requirements. Another misconception is that home equity borrowing is safe because the borrower has equity; the home remains collateral for the debt.

Frequently Asked Questions

Is a 401(k) loan the same as a hardship withdrawal?
No. A plan loan, when available, is borrowing with repayment terms. A withdrawal removes money from the account and has different plan and tax considerations. Check the plan rules and consult a qualified tax professional about individual tax questions.

Can I use this calculator for a home equity line of credit?
Only as a rough estimate if the balance, rate, and payment behave like a fixed-rate fully amortizing loan. A revolving line or changing rate needs a model that reflects its draw period, variable interest, and payment rules.

Does the calculator show the full cost of either option?
No. It estimates principal-and-interest payments from the inputs. It excludes fees and does not quantify home collateral risk, retirement investment effects, or plan-specific consequences.

What happens to a 401(k) loan if I change jobs?
The outcome depends on the plan’s terms and applicable rules. Ask the plan administrator how a job change affects repayment deadlines and the treatment of any unpaid balance.

Why can a longer term have lower monthly payments but higher interest?
The principal is repaid over more payment periods, spreading the scheduled amount out. Interest continues to accrue during those periods, so total interest can rise even if each payment is smaller.

This result is an estimate for education, and the lender’s disclosure gives the exact figures.

Related

• Borrowing Equity From Your Pension? What to Know
• Borrowing Equity From Your Home Loan Calculator
• Borrowing Equity From Your Home: Pros and Cons

in p | Loan amount | $ | 20000 | 1 | 100000000
in apr | Interest rate (APR) | % | 8 | 0.01 | 100
in yrs | Loan term | years | 5 | 0.0833 | 50
out pmt | Monthly payment | $ | p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)) | 2
out int | Total interest | $ | pmt * yrs * 12 - p | 2