Calculate your blended mortgage rate across multiple loans instantly. Combine first mortgage, second mortgage, HELOC, and other loans to find your true weighted mortgage rate, monthly payment estimate, and refinancing savings.
A weighted mortgage calculator computes the true average interest rate across multiple mortgage-related loans by weighting each rate by its outstanding balance. Unlike a simple average, it accurately reflects the fact that a $300,000 first mortgage at 6.5% contributes far more to your overall cost than a $30,000 HELOC at 9%.
Most homeowners with multiple loans (first mortgage, second mortgage, HELOC, home equity loan) don't know their true borrowing cost. The weighted mortgage rate gives you a single number to compare against refinancing offers, helping you make smarter financial decisions and potentially saving thousands in interest.
Your “true mortgage rate” is not the rate on your primary loan — it's the weighted average of all mortgage-related debt. If you have a 6.5% first mortgage and an 8% HELOC, your true rate is higher than 6.5%. Understanding this number is critical for evaluating refinancing, debt consolidation, and investment decisions.
Use this calculator when evaluating refinancing opportunities, combining multiple mortgages, adding a HELOC to your existing mortgage, comparing lender offers, planning debt consolidation, or analyzing investment property portfolios. It's essential for any homeowner carrying more than one mortgage-related loan.
Enter your primary mortgage's current outstanding balance, interest rate (APR), and remaining term in years. Use the balance from your latest statement — not the original loan amount.
Click “Add Loan” to include your second mortgage, HELOC, home equity loan, or any other mortgage-related debt. Enter each loan's balance, rate, and remaining term.
Instantly see your weighted mortgage rate, combined balance, estimated monthly P&I payment, annual interest cost, and visual breakdowns including balance distribution and interest contribution charts.
Compare your current separate mortgages vs a single consolidated loan. See if refinancing would save you money.
Refinancing saves money if you stay 28+ months.
The calculator multiplies each loan's balance by its rate, sums all products, and divides by total balance to get the weighted rate. For monthly payments, it uses the standard amortization formula for each loan individually, then sums all payments. This is more accurate than applying the weighted rate to the total balance, since each loan has a different remaining term.
A blended mortgage rate is a single interest rate that represents the combined cost of two or more mortgage loans. It is calculated by weighting each loan's rate by its balance, producing one number that reflects your true overall borrowing cost. Banks and lenders often use this term when offering to combine your existing mortgage with new financing.
In practice, “blended rate” and “weighted mortgage rate” produce the same mathematical result. The difference is context: “weighted mortgage rate” is a precise mathematical term, while “blended rate” is a lending industry term that may include additional factors like lender fees or rate locks depending on the institution.
Banks use blended rates when offering to combine your existing mortgage with additional financing (like a renovation loan or rate increase) without requiring a full refinance. This saves on closing costs while providing a single transparent rate. Understanding how blended rates work helps you evaluate these offers effectively.
| Method | How It Works | Example ($300K@6.5% + $50K@8%) | Accuracy |
|---|---|---|---|
| Weighted Mortgage Rate | Each rate is multiplied by its balance, summed, divided by total balance | (300K×6.5% + 50K×8%) ÷ 350K = 6.71% | ✓ Most Accurate |
| Blended Rate (Bank Method) | Same calculation as weighted, may include lender adjustments | Same as weighted: 6.71% (+ possible fees) | ✓ Accurate |
| Simple Average (Incorrect) | Add rates and divide by number of loans — ignores balances | (6.5% + 8%) ÷ 2 = 7.25% | ✕ Misleading |
The gold standard for calculating your true mortgage cost. It correctly weights each loan by its balance. The $300,000 first mortgage at 6.5% contributes 85.7% of the weight, pulling the average close to 6.5% rather than the midpoint of 7.25%.
Essentially the same weighted average calculation, but banks may layer on origination fees, rate locks, or credit adjustments. When a bank quotes a “blended rate,” ask whether it includes fees to ensure an apples-to-apples comparison.
Adding 6.5% + 8% and dividing by 2 gives 7.25%. This is wrong because it treats the $50K HELOC as equal to the $300K mortgage. The simple average overstates your true rate by 0.54% in this example, potentially causing you to pursue unnecessary refinancing.
The key difference is weighting. Both the weighted mortgage rate and blended rate account for loan sizes, producing an accurate single rate. The simple average ignores loan sizes and should never be used to evaluate mortgage costs. Always weight by balance.
Write down every mortgage-related loan: first mortgage, second mortgage, HELOC, home equity loan, and any other secured debt. For each, note the current outstanding balance and annual interest rate (APR).
For each loan, multiply the balance by the rate. Example: $300,000 × 6.5% = $19,500. This gives you the annual interest contribution of each loan.
Add all the products from Step 2. Example: $19,500 + $4,000 = $23,500. This is your total annual weighted interest across all loans.
Add all loan balances ($300,000 + $50,000 = $350,000). Divide total weighted interest by total balance: $23,500 ÷ $350,000 = 6.71%. This is your weighted mortgage rate.
When you add a HELOC to your existing mortgage, your true borrowing cost changes. HELOCs typically carry higher rates (7–10%) than first mortgages. Even a modest $40,000 HELOC at 8.5% on top of a $280,000 mortgage at 6.25% increases your weighted rate from 6.25% to 6.53%. This matters when evaluating refinancing.
A second mortgage (or home equity loan) always carries a higher rate than your first mortgage because the lender takes a secondary position. Adding a $75,000 second mortgage at 8% to a $250,000 first at 6.25% produces a weighted rate of 6.65% — not the 7.125% simple average, but still higher than your first mortgage alone.
Many homeowners treat their HELOC as separate from their mortgage, but lenders and your finances don't. Your HELOC balance increases your total mortgage debt and raises your weighted rate. As HELOC rates are often variable, your weighted rate fluctuates with market conditions. Use this calculator to monitor your true rate whenever your HELOC rate adjusts.
The core of your monthly mortgage payment. This calculator computes P&I using the standard amortization formula for each loan individually, then sums them. Early in the loan, most of the payment goes to interest; over time, more goes to principal.
Your full monthly housing cost includes property taxes and homeowner's insurance. To estimate PITI, add your annual property taxes ÷ 12 and monthly insurance premium to the P&I calculated here. PITI is what lenders use for qualifying you.
If your combined loan-to-value (LTV) exceeds 80%, you may pay Private Mortgage Insurance (PMI), typically 0.5–1% of the loan amount annually. PMI adds $100–$300/month for most borrowers. It drops off when your LTV reaches 78%.
Making extra principal payments reduces your balance faster, lowering your weighted rate over time (if the extra payment targets the highest-rate loan). Even an extra $100/month on a $300,000 mortgage at 6.5% saves $58,000+ in total interest and pays off the loan 5 years early.
See how your combined mortgage balance decreases over time and how interest vs. principal shifts year by year.
An amortization schedule is a table showing every payment over the life of a loan, broken down into principal and interest. In the early years, most of each payment goes to interest. By the end, nearly all goes to principal. Understanding this helps you see the true cost of borrowing.
On a $300,000 30-year mortgage at 6.5%, the first monthly payment is $1,896, of which $1,625 is interest and only $271 is principal. By year 20, it flips — $1,022 goes to principal and $874 to interest. The amortization heatmap above visualizes this shift.
Extra payments go directly to principal, accelerating payoff and reducing total interest. An extra $200/month on a $300,000 30-year mortgage at 6.5% saves $86,000 in interest and pays off the loan in 24 years instead of 30.
Track your remaining balance over time to determine your loan-to-value (LTV) ratio, which affects PMI eligibility, HELOC availability, and refinancing options. Use the amortization tool above to project when your LTV drops below 80% (the PMI elimination threshold).
Compare the refinancing offer's rate to your current weighted mortgage rate. If the offer is lower AND the monthly savings exceed closing costs within your planned stay period, refinancing makes sense. Use the comparison tool above to calculate your break-even point.
Break-even = Closing Costs ÷ Monthly Savings. Example: $6,000 closing costs ÷ $219 monthly savings = 27.4 months. If you plan to stay in the home longer than 28 months, refinancing saves money. Below that, closing costs eat your savings.
A cash-out refinance replaces your current loans with a larger loan, giving you cash. Your new rate applies to the entire amount. Compare the new weighted rate (on the larger balance) against your current weighted rate to see the true cost of the cash-out.
Consolidating a first mortgage + second mortgage + HELOC into a single loan simplifies payments and can reduce your rate. Use this calculator to find your current weighted rate, then compare it to consolidation offers. Any offer below your weighted rate saves money.
When you have a first and second mortgage, find your true blended rate to evaluate whether consolidating into a single loan makes financial sense.
Before opening a HELOC, see how it changes your weighted rate. After opening one, monitor your true rate as the HELOC balance and variable rate change.
Know your current weighted rate before shopping for refinance offers. Any offer below your weighted rate — with closing costs factored in — is worth pursuing.
Combine all mortgage-related debts to understand your total cost of housing debt. Compare against consolidation offers to find savings opportunities.
Know your true combined mortgage cost in a single number. Stop guessing — the weighted rate accounts for every loan's balance and rate, giving you an honest picture of your borrowing cost that simple averages can't provide.
Compare refinancing offers against your actual weighted rate. If a lender offers 6.25% and your weighted rate is 6.71%, you know immediately that refinancing saves money. Without the weighted rate, you'd be comparing to the wrong benchmark.
Identify which loans to pay down first for maximum impact. Paying down the highest-rate loan reduces your weighted rate fastest. The calculator's distribution chart shows each loan's contribution to find the most impactful target.
Plan your monthly housing budget accurately. The combined monthly payment estimate accounts for each loan's term and rate individually, giving you a precise total. Track your weighted rate quarterly to measure progress.
Adding 6.5% + 8% and dividing by 2 gives 7.25%, but your true rate is 6.71%. The simple average always overstates your cost when the larger loan has the lower rate — which is almost always the case with mortgages.
The weight of each rate depends entirely on its balance. A $300,000 loan dominates over a $30,000 loan. Always use current outstanding balances — not original loan amounts — for accurate results.
Many homeowners exclude their HELOC when calculating their mortgage rate. But HELOC balances are real debt with real interest costs. Including them reveals your true borrowing cost and may change your refinancing decision.
Refinancing has closing costs (typically 2–5% of the loan). If you don't factor these in, you may refinance for a 0.25% lower rate that takes 8 years to break even. Always calculate the break-even period before refinancing.
A weighted mortgage rate is the average interest rate across multiple mortgage-related loans, where each rate is weighted by its outstanding balance. For example, a $250,000 first mortgage at 6.5% and a $50,000 HELOC at 8% produce a weighted rate of 6.75% — not the 7.25% simple average.
Very similar. A weighted mortgage rate is a mathematical calculation that weights each rate by its balance. A blended rate is a banking term for a combined rate, usually calculated the same way but may include lender-specific adjustments or fees.
Multiply each loan's balance by its rate. Sum all products. Sum all balances. Divide total weighted interest by total balance. Example: ($300,000 × 6.5% + $50,000 × 8%) ÷ $350,000 = 6.71%.
Yes. Enter both your mortgage and HELOC balances and rates. The calculator will compute the true weighted rate across both loans and help you evaluate whether refinancing into a single loan makes financial sense.
In the weighted average calculation, the balance determines how much influence each rate has. A $300,000 mortgage at 6.5% has far more impact than a $25,000 HELOC at 9%. The larger the balance, the more it "pulls" the weighted average toward its rate.
It depends. Refinancing replaces existing loans with a new, typically lower-rate loan. Blending keeps existing loans. Compare the refinance rate to your weighted rate AND factor in closing costs. If monthly savings exceed closing costs within your planned stay, refinance. Otherwise, keep your current loans.
Yes. Enter each mortgage, HELOC, and home equity loan. The calculator handles unlimited loans and computes the weighted average across all of them.
Break-even = Closing Costs ÷ Monthly Savings. Example: $6,000 ÷ $219/mo = 27.4 months. If you stay in the home longer than 28 months, refinancing saves money. If shorter, closing costs eat your savings.
Rates vary by market conditions and credit score. In 2025, competitive 30-year fixed rates are typically 6.0%–7.5%. Use this calculator to find your current weighted rate and compare it to available offers.
This calculator focuses on interest rate and P&I payments. For full PITI estimates, add annual property taxes ÷ 12 and monthly insurance to the calculated P&I amount.
Specialized purpose-built weighted average calculators — each tailored to a specific domain with unique inputs, outputs, and interactive visualizations.