Biweekly Mortgage Payments: Do They Really Save Money?
It sounds like an accounting gimmick: same money, different calendar. But 26 half-payments equal 13 full ones — and that hidden 13th payment goes straight at your principal. Here's what it's actually worth, and when to skip the 'official' program.
The trick in plain numbers
On a $320,000, 30-year loan at 6.5%, the monthly payment is $2,022.62. Switch to paying $1,011.31 every two weeks and by year-end you've made 13 full payments instead of 12 — about $2,023 of bonus principal annually, without ever feeling a bigger bill.
| Monthly | Biweekly | |
|---|---|---|
| Effective payments/year | 12 | 13 |
| Payoff time | 30.0 yrs | ≈ 24.2 yrs |
| Total interest | $408,142 | ≈ $314,146 |
| Interest saved | — | ≈ $93,997 |
Roughly 6 years gone and $93,997 saved, from a payment your budget barely notices — most people just sync it with a biweekly paycheck.
Where the savings really come from
It isn't the two-week timing — that's worth only a few hundred dollars over the whole loan. It's the 13th payment. Every extra dollar of principal stops compounding interest on itself for the entire remaining term. That's also why the same trick works in simpler clothes:
- DIY version: add $168.55 (your payment ÷ 12) to every monthly payment, marked "apply to principal." Same math, zero enrollment, zero fees.
- Windfall version: one extra full payment each year from a bonus or tax refund.
Should the money go here at all?
A prepaid mortgage dollar earns your loan rate, guaranteed — 6.5% here. Compare before committing: high-interest card debt (20%+) beats it easily, an employer 401(k) match (an instant 50–100%) crushes it, and an emergency fund prevents the kind of borrowing that costs far more. Prepayment shines once those are covered.