Loan payment calculator
We use the standard amortizing loan formula. With P as the loan amount, r as the yearly rate divided by 12 and by 100, and n as the number of monthly payments, the payment is P x r x (1 + r)n / ((1 + r)n - 1). When the rate is zero, the payment is P divided by n. For the year-by-year table, each month's interest is the balance times r, and the rest of the payment reduces the balance. The last payment clears any rounding left over. An extra monthly payment is added to the principal each month, and the loan ends when the balance reaches zero.
Not included: fees, taxes, insurance, interest-only periods, balloon payments and changes in a variable rate.
Credit card dates
The due date is the statement date plus the days you enter. A purchase belongs to the next statement date on or after the purchase date. The grace period is the number of days from the purchase to that statement's due date. The late cost is the unpaid amount times the yearly rate divided by 365 times the days late, plus any fee you enter. Issuers can charge differently, so this is an estimate.
Bill reminder calendar
Each bill becomes a repeating all-day event in a standard .ics file, with an alert at 9 am the chosen number of days before. Bills repeat every 1, 3, 6 or 12 months on the day you pick (1 to 28).
How we check the results
Every time we update the site, we compare the loan formulas in the page against a separate calculation on hundreds of loan amounts, rates and terms, and we do not publish the update if any result differs.