How does the 401(k) loan limit get calculated?

The limit is the lesser of 50% of your Vested balance or $50,000, never below $0. Plans may also net outstanding loans against this cap.

What payment frequency should I choose in the calculator?

Match your payroll cycle: Weekly (52), Biweekly (26), Semi‑monthly (24), or Monthly (12). The frequency sets the number of payments and per‑paycheck amount.

Does the interest I pay on a 401(k) loan go back to me?

Typically yes—interest is credited to your account. Still, there’s an opportunity cost from pulling funds out of the market and potential taxes if the loan defaults.

Can I take a 401(k) loan for more than five years?

General‑purpose loans usually cap at 60 months. Primary residence loans may allow longer terms depending on plan rules.

What happens if I leave my job with a loan outstanding?

Many plans require quick repayment. If unpaid, the remaining balance can be treated as a taxable distribution and may incur penalties.

Are plan fees included in the calculator’s results?

No. The tool excludes origination and maintenance fees. Add them to evaluate total cost and effective rate.

Why is my requested loan marked ineligible?

Your amount likely exceeds the maximum allowable loan based on your Vested balance, or your entry is zero or blank. Reduce the amount or verify your vested funds.

401K Loan Calculator — Eligibility, Payments, and Total Cost

Use this tool to estimate your maximum 401(k) loan eligibility, per‑paycheck payment, and total interest cost. It answers three questions: how much you can borrow, what each payroll deduction will be, and how much interest you’ll pay over the term.

Quick start: get your payment and loan eligibility in minutes

Enter your Vested balance, Requested loan amount, Loan interest rate (APR, %), Term (months), and Payroll frequency. The calculator returns your maximum allowable loan, eligibility status, payment per paycheck, number of payments, and total repaid.

Start with Vested balance and Requested loan amount.
Set Term (months) — up to 60 for most general‑purpose loans.
Choose Payroll frequency to align with deductions.

How the math works behind the estimate and deductions

The model applies standard installment amortization with level payments and interest on outstanding principal. It also enforces statutory loan caps tied to your Vested balance.

Method and variables

Maximum allowable loan: capped at the lesser of 50% of your Vested balance or $50,000, never below $0.
Payment count: n = round(Term (months)/12 × payments/year).
Periodic rate: APR/100 divided by payments/year.
Payment per paycheck: if rate = 0, Requested amount/n; otherwise, Requested amount × rate ÷ (1 − (1 + rate)^(−n)).
Total repaid = payment × n; Estimated interest cost = Total repaid − Requested amount.

Key drivers: Vested balance (eligibility), Requested loan amount (principal), APR (cost), Term (affordability), and Payroll frequency (deduction size and count).

Worked example: from eligibility to per‑paycheck payment

Assume: Vested balance = $60,000; Requested loan amount = $15,000; Loan interest rate (APR, %) = 7%; Term (months) = 36; Payroll frequency = Biweekly (26/yr).

Maximum allowable loan = min(50% × $60,000, $50,000) = $30,000 → eligible for $15,000.
Payments/year = 26; n = round(36/12 × 26) = 78 payments.
Periodic rate = 7%/26 ≈ 0.2692% per pay period.
Estimated payment per paycheck ≈ $221.08.
Total repaid ≈ $17,244; Estimated interest cost ≈ $2,244.

Directionally: longer terms reduce each deduction but raise total interest. Higher APR increases both payment and interest cost.

401K Loan Calculator controls, definitions, and assumptions

Vested balance: only vested dollars count toward the limit and collateral.
Requested loan amount: must be > $0 and within the maximum allowable loan.
Loan interest rate (APR, %): plan‑set; interest is paid back into your account.
Term (months): typically ≤ 60 for general use; home‑purchase terms may be longer by plan rule.
Payroll frequency: Weekly (52), Biweekly (26), Semi‑monthly (24), Monthly (12).

Assumptions: level amortization; interest accrues on outstanding principal; rounding at the payment level; excludes plan fees and taxes; plan rules may vary.

Scenario comparison: adjust term or rate to test outcomes

Change the term length

Baseline (36 months, 7%, $15,000, biweekly): payment ≈ $221.08; interest ≈ $2,244.
Shorter term (24 months): fewer payments (≈52) → higher payment per paycheck, lower total interest.
Longer term (60 months): more payments (≈130) → lower payment per paycheck, higher total interest.

Change the APR

At 5% vs 7% (same term and amount): payment decreases modestly; lifetime interest drops notably.
At 0% (rare): payment equals principal divided by number of payments; interest cost is $0.

Insight: prioritize a shorter term if cash flow allows; small APR reductions compound over many pay periods.

Limits, pitfalls, and plan rules that commonly trip borrowers

Maximum cap: You can borrow up to the lesser of 50% of Vested balance or $50,000. If Vested balance is $20,000, max is $10,000, not $50,000.
Multiple loans: Plans may net outstanding loans against the cap; this tool assumes a single new loan.
Repayment timing: Missed payments can trigger deemed distributions and taxes.
Employment changes: Separation may accelerate payoff; otherwise, the balance could become taxable with penalties.
Fees: Origination or maintenance fees are excluded; add them to assess true cost.

Common mistake: using Current 401(k) balance instead of Vested balance for eligibility. Another: choosing an overly long term to minimize deductions, which inflates interest cost.

When a retirement plan loan might be reasonable vs alternatives

Cash‑flow fit: Payroll‑deducted payments create discipline but reduce take‑home pay.
Opportunity cost: Borrowed funds miss potential market gains; loan interest is credited back to your account.
Alternatives: Compare against a personal loan calculator, debt consolidation calculator, or a home equity loan estimator for rates and flexibility.

Trade‑off: lower headline cost than many credit cards, but potential investment return drag and employment risk exposure.

401k Loan Calculator

Table of contents