Quick answer
The saving comes from paying more each year, not from paying more often. Accelerated bi-weekly and accelerated weekly payments both add one extra monthly payment a year; regular bi-weekly, weekly and semi-monthly payments add none.
- Accelerated bi-weekly = monthly payment ÷ 2, paid 26 times a year = 13 monthly payments.
- Regular bi-weekly = monthly payment × 12 ÷ 26 = the same yearly total as monthly.
- On $500,000 at 5% over 25 years: accelerated saves about $60,400 and finishes in 21.5 years; regular bi-weekly saves about $1,900.
- You can get the same effect on monthly payments by adding one-twelfth of a payment each month, within your prepayment privilege.
What is the difference between bi-weekly and accelerated bi-weekly?
Both are paid every two weeks, 26 times a year. The difference is the size of the payment.
- Regular (non-accelerated) bi-weekly: your lender takes the yearly total of your monthly payments and divides it by 26. On a $2,908.02 monthly payment that's $1,342.16 every two weeks, or $34,896 a year: the same as monthly.
- Accelerated bi-weekly: your lender halves the monthly payment. That's $1,454.01 every two weeks, or $37,804 a year: $2,908 more, exactly one extra monthly payment.
Weekly works the same way. Regular weekly is the yearly total divided by 52 ($671.08); accelerated weekly is a quarter of the monthly payment ($727.01). Semi-monthly payments, twice a month on fixed dates, are 24 a year and add nothing extra.
Why do accelerated payments pay the mortgage off faster?
Because 26 half-payments equal 13 full ones. The Financial Consumer Agency of Canada puts it simply: by accelerating your payments, you make the equivalent of one extra monthly payment per year. All of that extra money goes on the principal, so every later payment has less balance to charge interest on.
Paying more often helps too, but only a little. Each payment reduces the balance a few days sooner, so slightly less interest builds up. That's why regular bi-weekly saves about $1,900 over 25 years, not zero. The big saving is the 13th payment.
How much does each payment frequency save?
| Frequency | Payment | Paid a year | Paid off in | Total interest | Saved vs monthly |
|---|---|---|---|---|---|
| Monthly | $2,908.02 | $34,896 | 25 years | $372,409 | None |
| Bi-weekly | $1,342.16 | $34,896 | About 25 years | $370,506 | $1,903 |
| Weekly | $671.08 | $34,896 | 24 years 11 months | $369,691 | $2,718 |
| Accelerated bi-weekly | $1,454.01 | $37,804 | 21 years 6 months | $311,973 | $60,436 |
| Accelerated weekly | $727.01 | $37,805 | 21 years 6 months | $311,282 | $61,127 |
Assumptions: $500,000 at a 5% fixed rate for the whole 25 years, compounded semi-annually, the convention for Canadian fixed-rate mortgages under the Interest Act; each frequency uses the matching rate per period; no other prepayments. Worked out payment by payment and checked against the standard formula. Round numbers for the arithmetic, not a forecast or a lender's rate.
Accelerated weekly saves a little more than accelerated bi-weekly, about $700 here, because the money arrives slightly sooner. Choose whichever matches your pay cheque; the difference is small.
What it looks like over 25 years
For the first few years the lines barely separate: the 13th payment is about $2,900 a year against a $500,000 balance. The gap widens every year, because each extra payment keeps saving interest for as long as the mortgage lasts.
- Monthly: 25 years
- Bi-weekly (not accelerated): about 25 years
- Accelerated bi-weekly: 21 years 6 months
Can I get the same saving on monthly payments?
Yes. Add one-twelfth of your payment to each monthly payment, or make one extra payment a year as a lump sum. On a $2,908.02 payment, one-twelfth is about $242 a month. Both count against your prepayment privileges, which on most closed mortgages easily cover this.
Some people prefer accelerated payments simply because they happen automatically and line up with being paid every two weeks. Others prefer monthly plus a yearly lump sum from a tax refund or bonus. The arithmetic is close; the habit is what matters.
Can I switch to accelerated payments in the middle of my term?
Usually yes. Many lenders let you change your payment frequency during the term, sometimes for a small fee, and every lender lets you choose a new frequency at renewal. Ask whether an accelerated payment counts against your payment-increase privilege; on some mortgages it does.
Are accelerated bi-weekly payments worth it?
For most people with spare cash flow, yes: it's a small, automatic increase that saves a large amount of interest. It isn't the right first step if the higher payment would leave you short, if you carry high-interest debt, or if you have no emergency fund.
And compare it with the other uses of the same money. About $2,900 a year into an RRSP gets you a tax refund at your marginal rate, which you could then put on the mortgage. Our guide on paying down the mortgage or investing runs that comparison at BC and Alberta 2026 rates, and the RRSP tax savings calculator shows your own refund.
How Finvo helps
We look at the tax side of where your spare money goes: what an RRSP, TFSA or FHSA contribution would save you, and what is left for the mortgage, as part of tax planning. Prices are on our pricing page.
Finvo is not a CPA firm, a financial planner, a mortgage broker or an investment adviser, and we don't sell loans, investments or insurance. Your lender sets up your payment frequency and explains your privileges. We work alongside them.
This guide is general information, checked against the Financial Consumer Agency of Canada's pages and the Interest Act on 5 Nov 2026. Your mortgage contract and your lender's rate decide your real numbers. It isn't financial, tax, legal or borrowing advice for your situation.