One frequent question I’m often asked is whether or not paying half of a mortgage payment twice a month versus paying a full mortgage payment once a month is actually worthwhile.

Let’s say, for example, you’re in the situation that Paul, one of my readers who wrote in recently, finds himself in. He just took out a $219,000 mortgage. His monthly payment on that mortgage is $1,300.89. Paul wants to know whether paying half of the mortgage twice a month will save him a significant amount.

The first thing he needs to do is make sure that his mortgage allows early payments – and how they work. Make a call to your lender and ask them how often interest is compounded (this needs to be daily or compounded monthly based on the average balance of the month – if it only compounds monthly, paying in advance won’t help), plus how multiple payments during a month are applied to your loan (they must be applied as soon as received for this to work). Most loans work this way, but not all.

There are two options with making early payments.

First, Paul can literally make two payments a month – say, on the fifteenth of every month and on the last day of every month. This means, over the course of a year, Paul pays the exact same amount in principle that he would otherwise pay. The only difference is that on the fifteenth of each month, he pays in half of his payment and at the end of each month, he pays in the remainder of his payment.

In my calculations in Excel, I assumed monthly compounding using the average balance of the last month. Using this method, I calculate that this method will save Paul just over two months’ worth of balance on the mortgage. He’d save $2,931.33 in interest, which would mean he would be able to skip his final two payments and make only a partial final payment.

However, a superior method of doing this would be to simply make a payment equal to half of the amount of the monthly mortgage bill every two weeks. Over the course of a year, this adds up to one extra full payment: since there are fifty two weeks in a year, you’d make 26 half payments, and thus 13 full payments.

In my calculations, I again assumed monthly compounding using the average balance of the last month. I calculated that this method will save Paul $41,117.09 over the course of the loan. His final, partial payment would be issued just shy of five years early.

This method falls perfectly in line with many income schedules (the federal government, for example, issues paychecks every two weeks), which means that you can just allot a certain amount from each paycheck directly toward your mortgage and then not think about it again.

For me, at least, twice-a-month payments would not provide enough benefit to be worth the management hassle of them unless it happened to line up directly with my paychecks.

On the other hand, biweekly payments – once every two weeks – do provide a lot of financial incentive to give them a shot. Add on top of that the fact that it’s directly in line with many pay schedules and that would seem to be a winner to me.

In a nutshell, simply paying twice a month doesn’t save much at all, but paying once every two weeks saves a lot. Yes, one or two fewer days per payment can save you tens of thousands at the end of the payments.

Good luck.