Refinance vs. Second Mortgage Calculator

It comes down to three numbers: your current first-mortgage rate, the penalty to break it, and how much new money you need. A low first-mortgage rate plus a big penalty usually favours adding a second; a first mortgage already at market rates, or a renewal date close by, usually favours refinancing. Run both above.

Variable-rate mortgages typically charge three months’ interest. Fixed-rate mortgages charge the greater of three months’ interest or the interest rate differential (IRD) — which on a low pandemic-era rate can run into the tens of thousands. Always request the exact payout quote from your lender before deciding anything.

When your first-mortgage rate is well below today’s rates, when the penalty is large, when you need a smaller amount, when you need money fast, or when bruised credit means a bank refinance isn’t available. The second costs a higher rate — but only on the new money, while your cheap first mortgage stays untouched.

At or near renewal (no penalty), when your existing rate is already at market, when you need a large amount over a long period, or when consolidating everything into one payment matters more than preserving an old rate. One mortgage at one mid-range rate often beats two mortgages long-term.

Bank refinances need strong credit and income, but B lenders refinance to 80% of value with flexible credit, and private lenders go further on equity alone. Pricing both a bruised-credit refinance and a second mortgage side by side is exactly what a broker does before recommending either.

Yes — that’s the standard exit. At your first mortgage’s renewal there’s no penalty, so the second gets consolidated into one new first mortgage. Many homeowners deliberately take a one-to-two-year second, then merge everything at renewal.