Blended Debt Rate

A blended interest rate is the single weighted-average rate that represents what you are really paying across several debts at once — each debt’s rate counted in proportion to its balance.

If you carry a $350,000 mortgage at 5% and a $275,000 second loan at 9%, you are not paying 5%, and you are not paying the simple average of 7%. You are paying a blended rate of 6.76%, because the larger 5% balance pulls the average down toward itself. The blended rate is the honest answer to “what is my overall cost of borrowing across everything I owe?”

It is the same idea a lender uses when deciding whether to keep a low first mortgage and add a second, or refinance everything into one new loan. This calculator does that weighting for you across up to 15 debts.

Blended rate = the sum of each debt’s (balance × rate), divided by the sum of all the balances — a balance-weighted average, not a plain average.

The formula in words: multiply every debt’s balance by its rate, add those up, then divide by the total of all the balances. Bigger balances carry more weight, which is exactly why a small high-rate card barely moves the number while a large mortgage dominates it.

Here is the worked example, the two default debts in this tool, step by step:

The calculator rounds the result to two decimals, the same way the underlying math does, and shows each debt’s share of the total so you can see what is driving the blend.

Use it whenever you are deciding between keeping a low first mortgage and adding a second loan, or wiping the slate clean by refinancing everything into one new rate.

Two of the most common situations:

• Keep the low first mortgage, add a second — if your existing mortgage is at 3.5% and you need more cash, a HELOC or second at 8% sounds expensive in isolation. Blend the two and you might still be at, say, 5% overall — far better than refinancing the whole balance into one 7% loan and losing your 3.5% rate forever.
• Refinance everything into one loan — if your blended rate across a mortgage, a car loan, and credit cards is 11%, a single consolidation loan at 8% genuinely lowers your blended cost. The calculator gives you the “before” number to compare any consolidation offer against.

It is also the cleanest way to talk about debt consolidation: compute the blended rate of everything you owe today, then see whether a proposed new loan actually beats it. If you also want to keep your existing low rate, our What Can I Afford tool helps size a second instead.

No — a lower blended rate does not always mean you pay less, because the rate ignores how long you will carry each debt.

This is the single most important caveat with blended-rate math. Rate is only half of total interest cost; time is the other half. Stretching a short, high-rate debt over a long new term can cost you more in total dollars even while the headline rate goes down.

So treat the blended rate as a rate comparison, not a total-cost verdict. A lower blend is a green light to investigate, not proof you will save. Always check the payoff timeline and total interest before you consolidate.

You can include up to 15 debts, and you need at least one with a positive balance.

Add any mix of debts that matters to you — a first mortgage, a second or HELOC, an auto loan, student loans, and credit cards all in the same view. Each debt takes a name, a balance (up to $10,000,000), and a rate (0% to 100%). When you reach 15, the add button locks with a “maximum reached” note.

Only debts with a balance greater than zero count toward the blended rate. Any zero-balance rows are flagged as “excluded from calculations” so they do not quietly distort the average — handy when you want to keep a paid-off debt on the list for reference without it affecting the math.

No — this tool weights by balance and rate only. It does not factor in each loan’s term, monthly payment, or payoff date.

That is by design: the blended rate answers “what is my overall interest rate right now,” a clean snapshot of today’s balances. It is deliberately simple so the number is easy to trust and easy to compare against a single consolidation offer.

But it also means the blended rate cannot tell you total interest paid or how fast you will be debt-free — those depend on terms and payments the calculator does not ask for. For a long-versus-short payoff decision, pair the blended rate with a full amortization comparison rather than relying on the rate alone.

A blended rate is the weighted-average interest rate across multiple debts; APR is the all-in yearly cost of a single loan, including its fees — they answer different questions.

They are complementary. Use the blended rate to see your overall borrowing cost today across all your debts. Use APR — from our APR Calculator — to compare the true cost of two competing loan offers, since APR folds in closing costs and points that a plain rate hides.

Because a plain average treats a $5,000 credit card the same as a $400,000 mortgage — and they are nowhere near equally important to your total interest bill.

Weighting by balance fixes that. Watch what happens when you add a small high-rate card to our two-debt example:

The plain average overstates your cost because it ignores that the cheaper mortgage is the much larger balance. The blended rate — 6.76% — is what you actually pay. A simple average is only correct in the rare case where every balance is identical.

Multiply your total balance by the blended rate and you get your approximate annual interest cost across all your debts — the practical reason the number matters.

In the two-debt example, $625,000 total balance at a 6.76% blended rate is roughly $42,250 a year in interest. That single figure is what makes the blended rate useful: it turns a pile of separate statements into one comparable cost you can act on.

It is an interest snapshot, not a full repayment schedule — balances fall as you pay them down, so next year’s figure will be lower. Use it to gut-check whether a consolidation or refinance offer is actually cheaper than what you carry today.

Enter each debt’s name, balance, and interest rate — the blended rate and a breakdown update instantly as you type.

• Start with the two sample debts, then edit them or add a debt (up to 15) for every balance you carry.
• For each row, type the balance and the interest rate — the name is just a label for the breakdown.
• Read the blended rate, your total balance, and each debt’s share of the total so you can see what is driving the number.

Everything runs in your browser and nothing is sent anywhere — it is informational, not financial advice. Once you have your blended rate, we can help you decide whether keeping your current loans or consolidating actually saves you money.