How to Compare Two Loan Offers by Total Cost
Compare two loan offers by total cost, not by the monthly payment or the headline rate. Work out what you receive, what you repay, and the difference. In one common case, a 36-month loan at 9% with a 1.5% fee and a 48-month loan at 7.5% with no fee cost almost the same in total, $1,597.90 against $1,605.87, yet the monthly payments differ by $76.21.
This guide shows the formula, a full worked comparison, and a short list of terms that change the answer.
The numbers to collect
Ask each lender for these figures in writing:
- Loan amount and the amount you actually receive after fees.
- Interest rate and whether it is fixed or variable.
- Term in months.
- Monthly payment.
- Upfront fees, such as an origination fee, and any other charges.
- The APR, which is the yearly cost including fees.
- Prepayment terms, meaning whether you can repay early without a penalty.
If a lender will not give a clear total, treat that as a warning. The figures should be simple to produce.
The payment formula
For a fixed-rate loan with equal monthly payments:
payment = P × i ÷ (1 − (1 + i)^−n)
P is the amount borrowed, i is the monthly interest rate (the annual rate divided by 12), and n is the number of monthly payments. Most calculators and spreadsheets use this formula, and a spreadsheet's payment function gives the same result.
Total repaid = payment × n.
Total cost of borrowing = total repaid − amount received.
Use the amount you receive, not the amount borrowed, because fees deducted at the start reduce the cash in your hand.
A worked example
Two offers for a $10,000 loan:
| Item | Offer A | Offer B |
|---|---|---|
| Amount borrowed | $10,000 | $10,000 |
| Interest rate | 9.0% | 7.5% |
| Term | 36 months | 48 months |
| Origination fee | 1.5%, deducted from the loan | None |
| Cash received | $9,850 | $10,000 |
The calculations:
| Result | Offer A | Offer B |
|---|---|---|
| Monthly payment | $318.00 | $241.79 |
| Total repaid | $11,447.90 | $11,605.87 |
| Total cost (repaid − received) | $1,597.90 | $1,605.87 |
Offer A's total cost is made up of $1,447.90 in interest plus the $150 fee. Offer B's is all interest, $1,605.87.
What the comparison shows
The total costs are almost equal: Offer B costs $7.97 more. The differences are elsewhere:
- Offer A has a higher payment, $76.21 more per month.
- Offer A is paid off 12 months sooner.
- Offer A delivers $150 less cash on day one.
So the real question is not which is cheaper, because they are close. The question is which payment you can carry comfortably, and whether you need the full $10,000 in hand.
APR & why it matters
The stated rate of 9.0% on Offer A is not what the loan really costs, because the fee reduces your cash. The cost taking the fee into account is about 10.04% a year in this example. The APR is meant to capture this, which is why you should compare APRs across lenders and also check the total in dollars.
Use APR to compare loans with the same term, and total cost to compare loans with different terms. A longer loan often has a lower APR and a higher total cost, because interest is charged for more months.
Four tests to apply
Run these checks on any two offers:
- Affordability. Can you pay the higher payment in your tightest month? If your income varies, test it against your lowest months, which a budget with irregular income makes easy to find.
- Total cost. Subtract cash received from total repaid.
- Flexibility. Does the lender allow early repayment without a penalty?
- Risk. Is the rate fixed? A variable rate can rise.
If one offer wins on total cost by a clear margin, say several hundred dollars, take it, provided the payment fits. If they are close, as in the example, choose by payment, term and flexibility.
Shorter versus longer terms
A shorter term raises the payment and lowers the total interest. A longer term does the reverse. In the example, extending from 36 to 48 months lowered the payment by $76.21 but added interest.
If you can afford the higher payment, a shorter term usually saves money. If you cannot, a longer term with no prepayment penalty gives you a way to pay extra when income is strong and still keep a lower required payment.
Extra payments
Extra payments toward principal reduce the interest you pay. Check whether the lender applies extra amounts to principal, and whether there is a fee. With Offer B's lower required payment, an extra $76.21 a month would bring the monthly total to about Offer A's, with the freedom to stop when needed.
Fees to look for
- Origination or application fees, often taken from the loan amount.
- Late payment fees.
- Prepayment penalties.
- Annual or account fees.
- Insurance products added to the loan.
Add any fee you will certainly pay to the total cost. Optional add-ons should not be included unless you choose them.
Fixed or variable rates
A fixed rate keeps the payment the same, which makes budgeting simple. A variable rate may start lower and rise. If you pick a variable loan, test the payment at a rate two or three points higher and see whether you could still afford it.
Check the effect on your budget
Before signing, put the new payment into your monthly plan. A loan payment is a fixed cost, so it reduces what you can put into savings goals. Look at your emergency fund and your yearly costs. Planned costs belong in sinking funds, and a smaller buffer is an argument for the lower payment.
Also confirm that you are not borrowing for something that could be bought with savings and planned spending. If you do not have a cushion, build a starter emergency fund first, even if your job is steady.
A comparison template
Copy this into a spreadsheet and fill in each offer:
| Item | Offer 1 | Offer 2 |
|---|---|---|
| Amount borrowed | ||
| Cash received | ||
| Rate and type | ||
| Term (months) | ||
| Monthly payment | ||
| Total repaid | ||
| Total cost | ||
| APR | ||
| Prepayment penalty? | ||
| Other fees |
Compute total repaid with payment × months, and total cost with total repaid minus cash received.
FAQ
Is the lowest interest rate always the cheapest loan?
No. Fees, the term and the way interest is charged all change the total cost. Compare total cost in dollars and the APR, not just the rate.
What is the difference between interest rate & APR?
The interest rate is the cost of borrowing the money. APR includes fees, so it gives a fuller picture of yearly cost. A loan with a low rate and high fees can have a higher APR than the rate suggests.
Is a longer loan term better?
It lowers the monthly payment but usually raises the total interest. It suits you if cash flow is tight, especially if early repayment is allowed.
Should I check my credit before comparing offers?
Rates depend on your credit profile, and checking your own report first helps you spot errors and understand what rate to expect. Compare offers you can actually receive, not just advertised rates.
Before you sign
Request the written figures from both lenders, calculate total cost with the formula, and test the payment against your lowest-income month. Choose the offer that fits your budget with the lowest total cost, and read the prepayment terms. Save the comparison table with the loan papers.
