Loan Comparison Calculator
Two offers, side by side. Enter the amount, the finance charge and the term for each, say whether it is repaid in one payment or in monthly installments, and the calculator returns the total, the APR, the cost per day and a one-line verdict on which offer costs less.
How the Loan Comparison Calculator Works
Two offers rarely arrive in the same shape. One is $500 due in two weeks with a $75 fee. The other is $500 over three months with $156.97 in interest. Same amount, different everything else. The calculator reduces each to three figures that can sit next to each other.
Total repaid is the amount plus the finance charge. APR for a single-payment loan is charge / amount x 365 / days. For an installment loan the calculator finds the monthly rate at which the stream of equal payments is worth exactly the amount borrowed, which is the actuarial method in Regulation Z Appendix J, then multiplies by 12. Cost per day is the finance charge divided by the days the loan runs, with a month counted as 365 / 12, or 30.42 days. The verdict line compares the two totals and says so in plain words.
Worked Example: Two-Week Loan Against a Three-Month Loan
Offer A: $500, $75 finance charge, one payment in 14 days.
- Total: 500 + 75 = $575.
- APR: 75 / 500 = 0.15. Times 365 / 14 (26.07) = 3.911, or 391.1%.
- Cost per day: 75 / 14 = $5.36.
Offer B: $500, $156.97 finance charge, three monthly payments.
- Total: 500 + 156.97 = $656.97, so each payment is 656.97 / 3 = $218.99.
- APR: find the monthly rate r where 218.99 x (1 - (1 + r)-3) / r = 500. At r = 0.15, (1.15)-3 = 0.6575, 1 - 0.6575 = 0.3425, 0.3425 / 0.15 = 2.2832, and 218.99 x 2.2832 = 500.0. So r is 15% a month, and 15 x 12 = 180% APR.
- Cost per day: three months = 91.25 days. 156.97 / 91.25 = $1.72.
Verdict: Offer A costs $81.97 less (656.97 - 575 = 81.97). That verdict holds only if $575 leaves your account in 14 days without breaking anything else. Roll Offer A once and its fees are $150. Roll it twice and they are $225, more than Offer B's entire finance charge, with the $500 still owed. Offer B costs about a third as much per day ($1.72 against $5.36) and never asks for more than $218.99 at once. Which one is better comes down to a single question: can you clear $575 on the next payday? The paycheck budget calculator exists to answer it.
Frequently Asked Questions
Which number should I trust when the two terms are different?
APR for the rate, total for the dollars, and your own budget for the schedule. A 14-day loan can have a lower total and a far higher APR than a 3-month loan for the same amount. The total is right only if you can repay on the date; the APR is right for comparing the price of credit; neither tells you whether the payment fits your paycheck.
Why does the calculator ask for the finance charge instead of a rate?
Because that is what short-term offers quote and what Regulation Z requires them to disclose: the finance charge in dollars and the APR. Most people have the dollar figure in front of them. If an offer gives you only a rate, run it through the installment loan calculator first and bring the dollar charge here.
What if an offer has an origination or document fee?
Add it to the finance charge. Regulation Z counts most fees a lender requires as a condition of the loan as part of the finance charge, and the APR on the disclosure already includes them. If you leave a $25 fee out, the calculator will understate that offer's total and APR by exactly that much.
My loan is due on a specific date, not in a round number of days. What do I enter?
Count the days from the day the money lands to the due date and enter that. A loan funded on the 3rd and due on the 24th is 21 days. Regulation Z lets lenders treat any period as a unit for APR purposes, so the actual day count is the honest input.
Can it handle biweekly installment payments?
Not directly. The installment option assumes equal monthly payments, which is how most installment loans are written. For a biweekly plan, enter the total finance charge and the term in months rounded to the nearest whole month; the APR will be close but a few points low, because payments arrive earlier than monthly. The total and the verdict are unaffected.
