How to Read a Mortgage Amortization Schedule

An amortization schedule is a complete table of every mortgage payment from loan origination through the final payment — showing how each payment is split between principal (balance reduction) and interest, and the remaining balance after each payment. The word "amortize" comes from the Latin for "to kill" — you are gradually killing the debt with each payment. A 30-year fixed mortgage generates a 360-row table (360 monthly payments). The key insight visible in any amortization schedule: interest is calculated on the remaining balance each month, so early payments are mostly interest (high balance × rate) and later payments are mostly principal (low balance × rate). See the amortization glossary entry for the foundational definition. Use the mortgage calculator to generate an instant amortization schedule for any loan scenario. The CFPB closing guide also covers how to read your final loan documents.

The standard mortgage payment formula: M = P × [r(1+r)^n] / [(1+r)^n − 1]. Where: M = monthly payment; P = principal (loan amount); r = monthly interest rate (annual rate ÷ 12); n = number of payments (years × 12). Example: $350,000 loan at 6.5% for 30 years. r = 0.065/12 = 0.005417; n = 360; M = $350,000 × [0.005417 × (1.005417)^360] / [(1.005417)^360 − 1] = $2,212/month. This fixed payment covers interest + principal each month — but the proportion shifts dramatically over time. Canadian mortgage calculation differs because of semi-annual compounding — the monthly rate is (1 + annual rate/2)^(1/6) − 1 instead of annual rate/12. See amortization glossary and use our mortgage calculator to verify calculations instantly.

Extra principal payments directly reduce the remaining balance, which reduces every subsequent month's interest charge — shortening the loan and reducing total interest paid. Example: $400,000 loan at 6.5%, 30 years. Standard: $2,528/month, $510,177 total interest paid. With $200 extra/month: loan pays off in ~25 years, total interest ~$418,000 — saving $92,000 in interest. With a single $10,000 lump sum at month 12: saves approximately $19,200 in interest and shortens loan by ~14 months. The earlier you make extra payments, the more interest you save — because you eliminate future compounding on the reduced balance. Most lenders allow prepayments without penalty on conventional loans (check your note for prepayment penalty clauses). See how to pay off your mortgage faster for comprehensive prepayment strategies and CFPB mortgage payment guidance.

An ARM (adjustable-rate mortgage) amortization schedule cannot be fully calculated in advance because the rate — and therefore payment — changes at each adjustment period. What you can calculate: (1) Initial fixed period (e.g., 5 years on a 5/1 ARM): The first 60 rows use the initial rate, exactly like a fixed-rate schedule; (2) After adjustment: Each new rate creates a new payment calculated on the remaining balance at that point — the schedule resets with the new rate applied to the remaining term; (3) Payment cap limits: Even if rates rise sharply, ARM payment caps limit how much the payment can increase per adjustment period. To read an ARM amortization schedule meaningfully, model multiple scenarios: current rate maintained, worst-case rate cap, and a moderate increase. See ARM glossary entry and understanding ARM caps.

Three key differences in Canadian mortgage amortization: (1) Compounding frequency: Canadian mortgages compound semi-annually (every 6 months) by law under the Interest Act. US mortgages compound monthly. This means a 6% Canadian mortgage has a slightly lower effective monthly cost than a 6% US mortgage; (2) Term vs amortization: Canadian mortgages have short terms (typically 1–5 years) within a longer amortization period (25–30 years). At each term end, the remaining balance is renegotiated. The amortization schedule shows total payments over the full amortization but the contract rate changes at renewal; (3) Maximum amortization: Insured (high-ratio) Canadian mortgages are capped at 30 years amortization (as of 2024 rule changes for new builds; 25 years for existing homes). Uninsured mortgages can go to 30+ years at some lenders. See amortization glossary, Canada amortization reform 2027, and the FCAC mortgage guide.

The amortization schedule is essential for accurate refinance analysis: Step 1 — find your current row in the schedule; note your remaining balance and remaining payments. Step 2 — calculate cumulative interest remaining on current loan (sum of all future interest payments). Step 3 — calculate cumulative interest on proposed new loan (new schedule for remaining balance at new rate and new term). Step 4 — add refinance closing costs to new loan's total interest. Step 5 — subtract old cumulative interest from new cumulative interest + costs = net savings (or cost). Break-even = closing costs ÷ monthly payment reduction. The critical insight: if you are 10+ years into a 30-year loan and refinance into another 30-year loan, you restart an interest-heavy schedule — potentially spending more in total interest even at a lower rate. A 15-year refinance may show less total interest than staying on the original 30-year, even at a similar rate. See how to refinance your mortgage and CFPB refinancing guide.