Both 401(k) Loan Calculator and Interest-Only Loan Calculator sit in the Loans & Debt category. They share an underlying model (loan amortisation plus foregone investment growth) but target different outcomes: 401(k) Loan on one side, Interest-Only Loan on the other.
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401(k) Loan Calculator computes 401(k) loan directly in your browser. It is built for sizing the true cost of borrowing from a 401(k) and uses loan amortisation plus foregone investment growth based on the inputs you provide.
Interest-Only Loan Calculator computes interest-only loan directly in your browser. It is built for generic loan payment and uses standard amortization formula based on the inputs you provide.
| Attribute | 401(k) Loan Calculator | Interest-Only Loan Calculator |
|---|---|---|
| Category | Loans & Debt | Loans & Debt |
| Primary input | 401(k) balance, loan amount, interest rate, term | Loan amount, interest rate, term |
| Primary output | Monthly payment, total interest, opportunity cost | Monthly payment, total interest paid |
| Math model | Loan amortisation plus foregone investment growth | Standard amortization formula |
| Best for | Sizing the true cost of borrowing from a 401(k) | Generic loan payment |
| Runs in browser | Yes, no data leaves your device | Yes, no data leaves your device |
| Login required | No | No |
| Cost | Free | Free |
Under the hood, 401(k) Loan Calculator uses loan amortisation plus foregone investment growth fed by 401(k) balance, loan amount, interest rate, term. Interest-Only Loan Calculator uses standard amortization formula fed by loan amount, interest rate, term. The two are not substitutes; they answer adjacent questions in your workflow.
Pick 401(k) Loan Calculator when your question is about 401(k) loan and your inputs are 401(k) balance, loan amount, interest rate, term. Pick Interest-Only Loan Calculator when the question shifts to interest-only loan and your inputs become loan amount, interest rate, term. If neither matches what you need, the Loans & Debt category hub lists every tool we have for related questions.
Your task is a focused, single task calculation and you already have tool specific input fields. The output you need is a single numeric or string result.
Your task is a focused, single task calculation and you have tool specific input fields. The output you need is a single numeric or string result.
Browse the Loans & Debt hub for related tools, or the Loans & Debt hub for the other side.
401(k) Loan Calculator is designed to answer questions about 401(k) loan using 401(k) balance, loan amount, interest rate, term. Interest-Only Loan Calculator is designed for interest-only loan using loan amount, interest rate, term. They are complementary tools that target different inputs and outputs.
Use 401(k) Loan Calculator when your task is sizing the true cost of borrowing from a 401(k) and you need a monthly payment, total interest, opportunity cost from 401(k) balance, loan amount, interest rate, term.
Use Interest-Only Loan Calculator when the question is generic loan payment and your inputs are loan amount, interest rate, term. The result is a monthly payment, total interest paid.
Yes. Both run entirely in your browser, require no login, and are free to use without limits. Your inputs are not transmitted to any server.
Accuracy depends on the inputs you provide, not on the tool. 401(k) Loan Calculator uses loan amortisation plus foregone investment growth and is accurate for 401(k) loan when its inputs are correct. Interest-Only Loan Calculator uses standard amortization formula and is accurate for interest-only loan under the same condition.