A 60-month $15,000 personal loan at 13% costs $2,283 more in total interest than a 36-month loan. The longer loan has lower monthly payments but a higher total cost.
The math
Inputs
| 36-month loan: amount | $15,000 |
|---|---|
| 36-month loan: APR | 13% |
| 36-month loan: term | 36 months (3 years) |
| 60-month loan: amount | $15,000 |
| 60-month loan: APR | 13% |
| 60-month loan: term | 60 months (5 years) |
The formula in words
For each loan: monthly payment = amount × r ÷ (1 − (1 + r)^−n), with r = APR ÷ 12 and n = months. Total interest = payment × months − amount. The cost of the difference is loan 2's total interest minus loan 1's.
Step by step
| Loan | APR | Term | Monthly payment | Total interest | Total paid |
|---|---|---|---|---|---|
| 36-month loan | 13% | 36 months | $505.41 | $3,195 | $18,195 |
| 60-month loan | 13% | 60 months | $341.30 | $5,478 | $20,478 |
| Month | Starting balance | Interest | Payment | To principal | Ending balance |
|---|---|---|---|---|---|
| 1 | $15,000.00 | $162.50 | $505.41 | $342.91 | $14,657.09 |
| 2 | $14,657.09 | $158.79 | $505.41 | $346.62 | $14,310.47 |
| 3 | $14,310.47 | $155.03 | $505.41 | $350.38 | $13,960.09 |
| Month | Starting balance | Interest | Payment | To principal | Ending balance |
|---|---|---|---|---|---|
| 1 | $15,000.00 | $162.50 | $341.30 | $178.80 | $14,821.20 |
| 2 | $14,821.20 | $160.56 | $341.30 | $180.73 | $14,640.47 |
| 3 | $14,640.47 | $158.61 | $341.30 | $182.69 | $14,457.78 |
| Year | 36-month loan | 60-month loan | Difference |
|---|---|---|---|
| Year 1 | $1,696 | $1,817 | $122 |
| Year 2 | $1,093 | $1,503 | $410 |
| Year 3 | $406 | $1,145 | $739 |
| Year 4 | $0 | $738 | $738 |
| Year 5 | $0 | $274 | $274 |
Result
- 36-month loan: monthly payment: $505.41
- 36-month loan: total interest: $3,195
- 36-month loan: total paid: $18,195
- 60-month loan: monthly payment: $341.30
- 60-month loan: total interest: $5,478
- 60-month loan: total paid: $20,478
- Difference in total interest: $2,283
- Difference in monthly payment: $164.11
Assumptions
- Fixed-rate loans with equal monthly payments, no fees and no early payoff.
- These are estimates that show how the math works, not financial, tax or legal advice. Lenders, card issuers and the IRS can calculate slightly differently.
Get help with this
Want help comparing your loan options? Leave your details and a specialist will reach out. It's free and there's no obligation.
What happens next: your details go straight to the FinancialPath team — no credit check and nothing to pay. Someone reads what you sent and gets back to you by email, phone or text. Tell us to stop and we stop.
What the $2,283 Difference Means for You
The $2,283 difference in total interest is the price you pay for a lower monthly payment. With the 36-month loan, you pay $505.41 each month and $3,195 in interest over three years. With the 60-month loan, you pay $341.30 each month but $5,478 in interest over five years. That extra $2,283 is not a fee or a penalty; it is simply the cost of borrowing the same $15,000 for two more years at 13%.
If you can comfortably afford the higher monthly payment, the 36-month loan saves you money overall. If the lower payment is necessary to fit your budget, the 60-month loan may be the only workable option, but you should go in knowing you will pay $2,283 extra for that flexibility.
Why the Longer Loan Costs More
Interest is charged on the balance that remains unpaid. With the 36-month loan, you pay down the $15,000 faster because each $505.41 payment covers more principal. With the 60-month loan, each $341.30 payment is smaller, so the balance shrinks more slowly and you pay interest on a larger balance for a longer time.
The APR is the same 13% for both loans, so the difference comes entirely from the term. The 60-month loan stretches the same amount over 60 months instead of 36 months. That means more months of interest charges, and because the principal is paid down more slowly, each of those months carries a higher balance than it would under the shorter loan.
The monthly payment trade-off
The 60-month loan lowers your monthly payment by $164.11. That is real breathing room in your budget each month. But over the full term, you make 24 more payments. Even though each payment is smaller, the total of those extra payments plus the slower principal reduction adds up to $2,283 more in interest.
How You Could Change the Outcome
Using only the numbers here, the main lever is the term. If you choose the 36-month loan, you pay $505.41 per month and $3,195 in total interest. If you choose the 60-month loan, you pay $341.30 per month and $5,478 in total interest. There is no middle option in these results, but you can see the trade-off clearly: shorter term means higher monthly payment and lower total interest.
Another factor is the APR. Both loans here use 13%. If a lender offers you a different rate, the interest totals will change, but the same principle applies: a longer term generally costs more in total interest when the rate is the same. The assumptions also say there are no fees and no early payoff. If your actual loan has fees or you pay it off early, the numbers will differ. Confirm the exact terms with your lender before you decide.
Practical Next Steps
First, look at your monthly budget. Can you handle $505.41 per month? If yes, the 36-month loan saves you $2,283 in interest. If that payment is too high, the 60-month loan at $341.30 may be safer for your cash flow, but plan for the higher total cost.
Second, ask your lender for the exact APR, fees, and payoff terms. The results here assume a fixed rate with equal monthly payments, no fees, and no early payoff. Your lender may calculate slightly differently.
Third, consider whether you can afford to pay more than the required monthly payment on the 60-month loan. The assumptions say no early payoff, so the $5,478 interest figure assumes you make only the scheduled payments. If you pay extra, you could reduce the total interest, but that outcome is not shown in these numbers. Ask your lender how extra payments are applied.
Finally, treat these figures as estimates, not advice. They show how the math works so you can compare the two terms. For your specific situation, confirm all numbers with your lender.
Frequently asked questions
Is the 60-month loan always more expensive?
When the APR is the same and you make only the scheduled payments, yes. In this example, the 60-month loan costs $5,478 in total interest versus $3,195 for the 36-month loan. The longer term means more months of interest and a slower principal payoff, so the total cost is higher.
What is the monthly payment difference between the two loans?
The 36-month loan has a monthly payment of $505.41. The 60-month loan has a monthly payment of $341.30. That is a difference of $164.11 per month. The lower payment is the main reason someone might choose the longer term despite the higher total interest.
Does the 13% APR change between the two loans?
No. Both loans use the same 13% APR in this example. The only difference is the term: 36 months versus 60 months. Because the rate is the same, the entire $2,283 difference in total interest comes from stretching the loan over more months.
Can I save money by paying off the 60-month loan early?
The results here assume no early payoff, so the $5,478 interest figure is based on making only the scheduled payments for 60 months. If you pay early, the actual interest could be lower, but that outcome is not calculated here. Ask your lender how early payoff would affect your specific loan.