Annuity vs Linear Mortgage: Which Saves You More?

An annuity mortgage — also called a level-payment or fixed-payment mortgage — divides your loan into equal monthly payments. Each payment includes principal and interest, but the proportion shifts over time. Early payments are mostly interest. Later payments are mostly principal. The total payment stays the same from month 1 to the final month.

This structure is mathematically elegant. It uses the time value of money to spread the cost evenly. The formula calculates how much you need to pay each month to fully amortize the loan by the end of the term.

Let's apply this to a $300,000 loan at 6% annual interest over 30 years. The monthly interest rate is 0.5% (6% / 12). The total number of payments is 360 (30 years × 12 months).

M = 300,000 × [0.005(1.005)^360] / [(1.005)^360 - 1] = $1,798.65

You will pay $1,798.65 every month for 30 years. The first payment includes $1,500 in interest (300,000 × 0.005) and $298.65 in principal. The second payment includes slightly less interest because your balance decreased by $298.65. This continues until the final payment, which is almost entirely principal.

Total payments over 30 years: $647,514. Total interest paid: $347,514 (647,514 - 300,000). You pay more in interest than the original loan amount.

A linear mortgage — also called a straight-line or constant amortization mortgage — pays down the principal in equal chunks every month. If you borrow $300,000 over 30 years, you repay $833.33 in principal each month (300,000 / 360). The interest is calculated on the remaining balance, so it decreases every month. Your total payment (principal + interest) decreases over time.

The formula is simpler than the annuity version. You calculate the fixed principal payment once, then add the interest based on the current balance.

Using the same $300,000 loan at 6% annual interest over 30 years:

• Fixed principal payment: $300,000 / 360 = $833.33 per month
• Month 1 interest: $300,000 × 0.005 = $1,500.00
• Month 1 total payment: $833.33 + $1,500.00 = $2,333.33

After the first payment, your balance drops to $299,166.67. Month 2 interest is $299,166.67 × 0.005 = $1,495.83. Month 2 total payment is $833.33 + $1,495.83 = $2,329.16. The payment decreases by about $4 per month because the interest portion shrinks.

By month 180 (halfway through the loan), your balance is $150,000. Interest is $150,000 × 0.005 = $750. Total payment is $833.33 + $750 = $1,583.33. By the final payment, you owe only $833.33 in principal and almost no interest.

Total payments over 30 years: $570,750. Total interest paid: $270,750 (570,750 - 300,000). You save $76,764 compared to the annuity mortgage.

Let's compare these two repayment structures at three points in time: the first month, the midpoint (month 180), and the final month. Same loan: $300,000 at 6% annual interest over 30 years.

The linear mortgage saves you $76,764 over 30 years. That is a 22% reduction in total interest paid. The trade-off is a higher initial payment: $2,333 versus $1,799 in month 1. But by month 13, the linear payment drops below the annuity payment and stays lower for the remaining 348 months.

The linear mortgage always saves money compared to an annuity mortgage with the same terms. This is not a trick or a loophole — it is basic math. You pay down principal faster with a linear mortgage, so you owe interest on a smaller balance each month. Less balance means less interest. Less interest means lower total cost.

The savings scale with the loan size and term. On a $300,000 loan at 6% over 30 years, you save $76,764. On a $500,000 loan at the same rate, you save $127,940. On a 15-year term, the savings are smaller because the loan is repaid faster either way.

Interest rates amplify the difference. At 4%, the savings on a $300,000 / 30-year loan drop to about $48,000. At 8%, the savings jump to over $107,000. Higher rates mean more interest, and the linear structure cuts deeper into that cost.

If your only goal is to minimize the total amount you pay over the life of the loan, the linear mortgage wins. No exceptions. But total cost is not the only factor.

The annuity mortgage wins on predictability. Your payment is the same every month for the entire term. You know exactly what you will owe in year 1, year 15, and year 30. This simplifies budgeting, automates payments, and eliminates surprises. Most people value this stability, especially when managing other variable expenses.

The linear mortgage requires more financial flexibility. Your first payment is significantly higher than the annuity equivalent. In our $300,000 example, that is an extra $534 per month initially. If you are stretching to afford the house, that difference can matter. Banks typically qualify borrowers based on the initial payment, which means you might qualify for a smaller loan with a linear mortgage.

However, the linear payment decreases over time. By year 10, your payment is lower than the annuity equivalent. By year 20, it is substantially lower. If your income grows over the life of the loan — which is typical for most careers — the linear structure aligns better with your cash flow. You pay more when you earn less (early career), but the payment shrinks as your income rises.

The annuity structure does the opposite. It keeps the payment constant, which means the burden feels heavier as your income increases. A $1,799 payment might be tight in year 1 but trivial in year 25 when you earn twice as much. The linear mortgage adjusts the payment to match your improving financial position.

Geography shapes which repayment structure dominates. In the United States, Canada, and the United Kingdom, the annuity mortgage is the default and often the only option offered by mainstream lenders. Linear mortgages are rare to nonexistent in these markets. Most American borrowers do not know linear mortgages exist.

In the Netherlands, the linear mortgage (lineaire hypotheek) is common and widely understood. Dutch banks offer both types, and borrowers actively compare them. The linear structure is often recommended for higher-income households who can handle the initial payment and want to minimize total interest.

Nordic countries (Sweden, Norway, Denmark, Finland) also offer both types, though the annuity structure is more popular. In Germany, the Tilgungsdarlehen (linear repayment loan) exists but is less common than the annuity version.

The cultural and regulatory differences explain why one structure dominates in certain markets. In the U.S., predictability and standardization are prioritized. The 30-year fixed-rate annuity mortgage is a cornerstone of the housing finance system, backed by Fannie Mae and Freddie Mac. In the Netherlands, financial literacy is higher, and borrowers are expected to evaluate trade-offs between payment structure and total cost.

If you have access to both options — which is rare in the U.S. but common in the Netherlands and some other European markets — here is how to decide:

Choose annuity if:

• You prioritize predictable payments and simple budgeting over total cost savings.
• Your income is stable but not expected to grow significantly over the loan term.
• You are stretching to afford the home and cannot handle a higher initial payment.
• You plan to refinance or sell within 10-15 years (the interest savings from linear only compound over the full term).

Choose linear if:

• You can comfortably afford the higher initial payment and want to minimize total interest paid.
• Your income is expected to grow over the loan term (early to mid-career professionals).
• You value building equity faster — the linear structure pays down principal more aggressively early on.
• You plan to hold the mortgage for the full term or close to it.

Tax considerations: In some countries, mortgage interest is tax-deductible. The linear mortgage generates less total interest, which means smaller tax deductions. If you are in a high tax bracket and rely on mortgage interest deductions, the annuity structure might be more tax-efficient in the short term. However, the linear structure still saves money overall once you account for lower total interest.

Prepayment strategy: If you plan to make extra principal payments on an annuity mortgage, you can mimic the savings of a linear mortgage. Many borrowers pay extra toward principal when they can afford it, accelerating payoff and reducing interest. This hybrid approach gives you the flexibility of an annuity structure with the cost savings of a linear structure — but it requires discipline and financial surplus.

The annuity and linear mortgage are two ways to structure the same loan. The annuity mortgage fixes your payment, simplifies budgeting, and spreads the cost evenly over time. The linear mortgage decreases your payment over time, saves money on total interest, and aligns better with rising income. One optimizes for predictability. The other optimizes for cost.

In markets where both are available, the choice depends on your cash flow, career trajectory, and priorities. If you can handle the higher initial payment and plan to hold the mortgage long-term, the linear structure saves tens of thousands of dollars. If you value stable payments and are unsure about future income, the annuity structure reduces risk and simplifies planning.

Most borrowers never get to make this choice. The annuity mortgage is the only option in the U.S. and similar markets. But understanding the alternative clarifies why your payment is structured the way it is — and how the math works behind the scenes.