What this tool does
This calculator turns a purchase into a payment schedule. Pick how the plan charges you, enter the price, the number of months and the rate, and every payment appears in a table with its principal, its interest or fee, the amount due and the balance still owed afterwards. Totals and the cost of the plan as a share of the price sit underneath.
Three kinds of plan are covered. Equal monthly payments is how most buy-now-pay-later loans, phone plans and personal loans work: the same amount every month, with interest on the balance at the APR divided by twelve. With $1,000 over 12 months at 10% APR the payment is $87.92 and the interest $54.99, the same as a standard amortization calculator. Fee on what's left is the card-installment style used in Korea: equal slices of the price plus interest on the balance, so the first payment is the largest. Fixed monthly fee covers card plans that charge a set percentage of the purchase each month instead of interest.
How to use it
- Choose the kind of plan your lender or card offers.
- Enter the purchase price, pick the number of months and type the APR (or, for a fixed-fee plan, the monthly fee as a percent of the price). For a 0% plan type 0.
- Read the schedule and the totals. Long plans show the first twelve payments; open the full list with one button.
- Press Print to put the schedule on one A4 or letter page, or save it as a PDF from the print window.
APR versus a fixed monthly fee
A fixed monthly fee looks small, but it is charged on the full price every month, even when most of it has been repaid. A $1,200 purchase over 6 months with a 1.72% monthly fee costs $20.64 a month in fees, $123.84 in total. The same purchase on equal payments at 20.64% APR, the fee rate times twelve, costs $73.26 in interest, because interest shrinks with the balance. Switch between the plan types to compare the offer in front of you.
The fee share line shows the cost of the plan as a percent of the price, which makes plans of different lengths easier to compare than their rates alone.
How the numbers are rounded
Amounts are worked out in whole cents. Each month's interest is rounded to the cent and the last payment settles whatever is left, so the principal column always adds up to the price exactly. Card-style plans split the price into equal parts and add any leftover cents to the first payment.
Your data
The price and the dates you enter are calculated in this browser only and are never sent anywhere. They are not saved either; only your choice of plan, months and rate is remembered in this browser for next time.
Questions and answers
Why is my lender's schedule a few cents different?
Lenders may count interest by the exact number of days between payments, or round differently. The calculator rounds each month's interest to the cent; the schedule in your agreement is the one you pay.
Can I calculate a 0% plan?
Yes. Type 0 as the rate and the schedule shows the price split into equal payments with no interest. Remember that some 0% offers charge deferred interest if the balance is not paid in full in time.
What does the balance column mean?
It is the principal still owed after that payment, the amount you would need to pay off the plan early (before any payoff fees your lender may charge).
Which plan type should I choose?
If your offer shows an APR and the same payment every month, choose equal monthly payments. If it shows a fixed monthly fee, choose the fixed fee plan. Fee on what's left matches card installments that add interest on the remaining principal.
