Fixed vs Variable Rate Mortgage: Total Cost Comparison

Published August 2, 2026 · 5 min read

Choosing between a fixed and variable rate mortgage is one of the biggest financial decisions most people make. The choice affects your payment stability, your total interest cost, and your ability to budget confidently for decades. Neither option is universally better. The right answer depends on your situation and what matters most to you.

Fixed Rate Mortgages: What You Are Paying For

With a fixed rate mortgage, your interest rate stays the same for the entire loan term. Your monthly payment is predictable from day one. You know exactly what you will pay every month in year 3, year 12, and year 28. That predictability has real value, especially for households where budget stability is important.

The downside is that fixed rates are typically higher than the starting rate on a variable loan. You are paying a premium for the certainty. If interest rates fall significantly during your loan term, you are locked in at the higher rate unless you refinance, which costs money and requires qualifying again.

Variable Rate Mortgages: What You Are Betting On

Variable rate mortgages, sometimes called adjustable rate mortgages or ARMs, start with a lower rate than fixed mortgages. That lower starting rate means lower initial payments and more of each payment going to principal early in the loan. If rates stay flat or fall, you come out ahead compared to the fixed option.

The risk is that rates can rise. Most variable rate mortgages have caps that limit how much the rate can increase in a single adjustment period and over the life of the loan. But even with caps, a significant rate rise can push your payment well above what you initially planned for. If your budget is not comfortable with that scenario, variable rate adds real financial stress.

A Real Cost Comparison

Let's run the numbers on a $250,000 mortgage with a 30-year term using three scenarios.

Fixed rate at 6.5%: Monthly payment = $1,580. Total interest paid = $318,817. Total cost = $568,817.

Variable rate starting at 5.5%, stays flat: Monthly payment = $1,419. Total interest paid = $261,016. Total cost = $511,016. You save about $57,800 if the rate never moves.

Variable rate starting at 5.5%, rises to 7.5% after 5 years: The math gets more complex but the higher rate in later years erodes much of the early savings. Total interest in this scenario approaches or exceeds the fixed option, while you also absorbed the stress of payment increases along the way.

When Fixed Rate Makes More Sense

Fixed rate mortgages tend to be the better choice when current rates are historically low relative to the long-term average and you expect rates to rise. They also make sense when your income is fixed or predictable and a payment increase would be genuinely difficult to absorb. If you are planning to stay in the home for more than seven years, fixed rate gives you more certainty over a longer period.

When Variable Rate Makes More Sense

Variable rates tend to favour borrowers who plan to sell or refinance within 5 to 7 years, before the adjustment period kicks in meaningfully. They also work better when fixed rates are relatively high and expected to fall, meaning the variable rate saves money up front and you benefit if rates decline. Borrowers with higher incomes and financial flexibility can absorb payment changes without the stress that would affect someone on a tighter budget.

The Hybrid Option: Fixed ARM Periods

Many variable rate mortgages offer a fixed period upfront before the rate begins adjusting. A 5/1 ARM is fixed for the first 5 years, then adjusts annually after that. A 7/1 ARM is fixed for 7 years. These can offer the best of both worlds for people who plan to move or refinance within that initial fixed window. The starting rate is lower than a fully fixed 30-year loan, but you have predictability for the period when you are most likely to be in the home.