Blended Rate Calculator
Calculate the true weighted average interest rate across multiple loans or debts to evaluate debt consolidation options accurately.
| Loan | Balance | Weight (%) | Rate | Annual Interest |
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What is a Blended Rate?
A blended rate is the weighted average interest rate calculated across multiple loans or debt instruments. Unlike a simple average—which treats all loans equally regardless of size—a blended rate factors in the principal balance of each loan. Loans with higher balances exert more influence (weight) on the final blended rate than smaller loans.
In personal finance, calculating a blended rate is the most mathematically accurate way to understand the true cost of your combined debt. It is commonly used to determine whether debt consolidation will actually save money.
Blended Rate Formula
To calculate a blended rate, you multiply each loan's interest rate by its outstanding balance, sum those totals together, and divide by the total aggregate debt.
Why You Shouldn't Use a Simple Average
If you simply averaged the rates in the example above (15% + 5% / 2), you would get 10%. However, because the 5% loan is four times larger than the 15% loan, the true cost of your debt is heavily pulled toward the lower rate. The actual blended rate is 7%. Using a simple average creates a false sense of your debt cost and can lead to poor financial decisions, such as taking out a consolidation loan at 9% thinking you are saving money, when in reality, you are losing money.
Primary Use Cases for a Blended Rate
1. Debt Consolidation Analysis
Before merging credit cards, personal loans, and medical bills into a single consolidation loan, calculate your current blended rate. If a lender offers you a consolidation loan at a rate lower than your blended rate, consolidation will save you money on interest. If the offered rate is higher, you should not consolidate.
2. Combining First and Second Mortgages
Homeowners often have a primary mortgage at one rate and a Home Equity Line of Credit (HELOC) or second mortgage at a different, usually higher, rate. The blended rate tells them their effective borrowing cost across the total property debt.
3. Corporate Finance and WACC
In business, companies calculate a blended rate across all their debt instruments (bonds, bank loans, credit lines) to determine their cost of debt. This is a core component of calculating the Weighted Average Cost of Capital (WACC).
Step-by-Step Guide to Using This Calculator
- List all debts: Enter the exact outstanding balance and the exact annual percentage rate (APR) for each debt.
- Add rows as needed: Use the "Add Another Loan" button to input as many debts as necessary.
- Calculate: The engine instantly computes the weighted average.
- Analyze: Use the built-in consolidation tool to input a hypothetical new interest rate and see exactly how much you would save or lose in annual interest.
