Why is the rate alone not enough?
A loan with a low interest rate can still cost more than it looks, if it carries upfront fees. The fees reduce the amount you actually receive, so the rate you really pay is higher than the stated rate. The annual percentage rate, or APR, spreads the fees across the loan to show that higher figure.
How do I use it?
Enter the loan amount, the stated rate, the term, and the fees you pay up front. Compare the APR with the stated rate, then compare the APR of two offers to see which one is cheaper.
How does the calculation work?
The calculator finds the monthly payment from the amount and the stated rate. Then it searches for the monthly rate at which the payments are worth the amount left after fees. That monthly rate is multiplied by the months in a year to give the APR.
What can the result not tell me?
Lenders disclose their own APR under the law, and that disclosed figure is the one to rely on. This calculator follows the same idea, but it may leave out some charges that a lender counts. Use it to compare offers, and check the lender's figure before you sign.
Why the interest rate alone is not enough
A loan offer often shows an interest rate that looks attractive, but the rate does not include every cost. Origination fees, processing charges, and some other upfront amounts can make the loan more expensive than the rate suggests. The annual percentage rate article on Wikipedia explains that the APR is the interest rate for a whole year, and that it must include certain non-interest charges and fees.
Because the APR folds fees into a single yearly rate, it gives you a fairer way to compare offers. Two loans with the same interest rate can have different APRs once their fees are counted. The calculator shows that difference so you can see it clearly.
Entering the amount, rate, term, and fees
Enter the amount you are borrowing, the interest rate before fees, the term in years, and the upfront fees charged on the loan. Be exact with the fee amount, because a small difference in fees can change the APR noticeably on a short loan.
Check whether the fee is paid upfront or added to the loan balance. The calculator treats the fee as part of the cost of borrowing either way. If the lender lists several fees, add them together before entering the total.
Reading the APR and the monthly payment
The calculator returns the APR including fees and the monthly payment. The APR is the comparison figure. The monthly payment is the cash flow figure. A loan with a lower payment may still have a higher APR if its fees are high, so look at both before you choose.
Remember that the payment shown is an estimate based on the inputs you entered. The lender's contract will list the official payment, and it may differ if the terms are different from what you typed.
Where the calculation can mislead
The APR assumes the loan runs to the end of its term and that every payment is made on time. Early payoff can change the real cost, and so can a loan that carries a prepayment penalty. The calculation also assumes a fixed rate. A variable-rate loan can move away from the APR you calculated.
Some fees are not included in the APR, such as late fees or charges for optional add-ons. Check the disclosure documents for any charge that is not listed in the offer summary.
Comparing two or more offers fairly
Run the same inputs for each offer, using the same term where you can. Comparing a short term against a long term with only the APR can be misleading, because the total cost depends on the length of the loan as well as the rate.
For a side-by-side view of several offers, the loan comparison calculator puts two offers next to each other. Use the APR to decide which offer is cheaper, and the monthly payment to decide which one fits your budget.
How fees change the APR
When fees are added to the loan, the amount you actually receive is smaller than the amount you owe. That gap raises the true cost of borrowing. The APR captures this by spreading the fees across the term as if they were part of the rate. On a short loan, the same fee has a bigger effect on the annual figure than on a long loan.
This is why two loans with the same stated rate can have quite different APRs. Read the fee list carefully, and confirm which charges are included in the APR disclosure. Some fees are optional or are charged only in certain situations, and those may not be counted.
Questions to ask a lender about the APR
Ask the lender to show the APR in writing, along with the total of all payments. Ask which fees make up the APR and whether any fees are not included. Ask whether the APR assumes the loan is paid to the end of the term, and what happens if you pay early.
Keep the written answers with your records. If a figure changes between the offer and the contract, you will have the documents to ask why. The calculator gives you a way to check the arithmetic, but the official disclosure is the document that governs the loan.
Using the APR to plan the total cost
Once you have the APR, use it to estimate the total cost over the term. The monthly payment multiplied by the number of payments gives the total repaid, and the difference from the amount borrowed is the cost of the loan. Comparing that total across offers is often more useful than comparing rates alone.
Remember that the APR is an annual measure. If you repay early, the actual cost of the loan may be lower than the APR suggests, depending on the fee structure. Ask the lender how an early payoff is treated before you assume the savings.
Comparing an APR with a promotional rate
A promotional rate is often lower than the rate that follows it. The APR may reflect only the introductory period, or it may describe the rate after the promotion ends. Read the disclosure to see which applies, and ask the lender for the full schedule of rates over the term.
When you compare a promotional offer with a standard one, use the rate that applies for most of the loan, not just the first months. A short promotion can make a loan look cheap while the later years cost much more. The calculator is most useful when the inputs reflect the full term.
Keeping the APR in context
The APR is an important figure, but it is one input in a larger decision. The purpose of the loan, the reliability of the income that will repay it, and the cost of the alternatives all matter. A loan with a slightly higher APR can still be the right choice if it solves a problem that a cheaper option would not.
Use the APR to compare like with like, and then step back to ask whether the loan is needed at all. That final question is often the most valuable one in the whole process.
