Blended Interest Rate Calculator
Combine multiple loan balances and interest rates into one weighted average blended rate. Useful for debt consolidation analysis, refinancing comparisons, mortgage + HELOC scenarios, and understanding the true average cost of debt across several accounts.
Enter your loan balances and rates
Add each debt with its balance and annual interest rate. The blended rate weights each rate by its balance โ larger balances influence the result more.
What is a blended interest rate?
A blended interest rate is the weighted average of multiple interest rates, where each rate is weighted by its corresponding balance. It gives you a single number that represents the combined borrowing cost across all your debts.
Unlike a simple average (which treats every rate equally), a blended rate reflects the actual impact of each balance. A large mortgage at 6% will dominate a small credit card at 20%, because the mortgage balance is so much larger.
Blended interest rate formula
The formula is a weighted average:
Example with 2 loans:
How to use this blended rate calculator
- Enter the balance for each loan, mortgage, credit line, or debt account.
- Enter the matching annual interest rate (not APR) for each balance.
- Click + Add loan to add more rows if you have more than 2 debts.
- Click Calculate Blended Rate to see your weighted average.
- Use the result to evaluate whether consolidating makes financial sense.
When to use a blended rate
A blended interest rate is most useful in these situations:
Frequently asked questions
What is a blended interest rate?
A blended interest rate is the weighted average interest rate across multiple loan balances, where larger balances affect the final rate more. It gives you a single number representing your combined borrowing cost.
Why is a blended rate different from a simple average?
A simple average treats every rate equally regardless of balance size. A blended rate weights each rate by its balance, which is more accurate for real-world debt analysis. A $200,000 loan at 6% matters far more than a $2,000 loan at 20%.
Can I use this for mortgage and HELOC combinations?
Yes โ this is one of the most common use cases. Enter your primary mortgage balance and rate as one row, and your HELOC balance and current rate as another. The result is your combined home debt cost.
Should I use the interest rate or APR?
Use the annual interest rate (not APR) for each loan. APR includes fees and other costs that make cross-loan comparison less clean. For pure rate-blending purposes, the stated interest rate gives the most accurate weighted average.
If a consolidation loan rate is lower than my blended rate, should I refinance?
A lower rate than your blended rate is a positive signal โ but not the only factor. Also consider closing costs, loan term length, whether the rate is fixed or variable, and whether you'll actually pay off the consolidated loan faster or just extend it.
Related finance calculators
These tools work naturally with your blended rate analysis.
Disclaimer
This blended interest rate calculator is for educational and planning purposes only. It uses stated interest rates and does not account for fees, origination costs, APR, variable rate changes, or prepayment terms. Consult a licensed financial advisor before making debt consolidation or refinancing decisions.