Hey folks, Trying to help my mother out and fill my own curiosity. Anyone know a link that can tell you what the effective APR is after a lumpsum payment to a loan? My mom took a loan $21K, 4.69% apr, 72 months, 367 a month payment, She pays $600 a month and took $4000 out of her tax refund and made a lumpsum principle payment. LOL, she started out before she realized she had to specifiy extra payments have to specified as principal and now she actually doesn't have a payment due until nov 2013.
Anyways, What I want to find out, is what the actuall effective interest rate she is paying with her lumpsum and overpayments to principle. Can anyone tell me what the formula is or point me in the direction of a calculator?