<prompt> Human: So say I take out a 500,000 mortgage, and monthly payments are 3,000 2k interest, 1k principleLets say for the first payment I pay 6000 twice the amount I need to. My understanding is that that 6000 would be divided into 2k interest, 4k principle.My question: Does that 6000 payment affect the interest paid on the next payment or is that all fixed ahead of time?  <response>: The interest due is calculated each month based on the balance at the time. Your payment wouldnt change, but the interest portion of the payment would be lower and the principal portion would be higher than it would had you not made the extra payment. 