Blended rate calculator.

Keep your low mortgage rate and add a HELOC, or replace it with one cash-out refinance? See the blended rate of each path, the monthly payments, the interest over the years you choose, and the current rate where the answer flips. Results show as you type, with no email.

Your mortgage and the cash you need

How long you expect to keep these loans before you sell or refinance again.

Option 1: cash-out refinance

Example: 7.40% is the 30-year fixed Freddie Mac average for the week of Oct 15, 2026 (15-year: 6.71%). Use the rate a lender quotes you for a cash-out loan.

New term
Closing costs

Freddie Mac says refinancing typically costs 3% to 6% of the loan.

3% of the new loan is $9,897.

Common with cash-out loans. Unchecked, you pay them at closing.

Option 2: keep your loan and add a HELOC

Example rate: the prime rate as of Oct 20, 2026, 7.00%, plus a 1.00% margin; your lender sets the margin. Some lenders waive up-front HELOC costs and others charge appraisal and closing fees.

Your two paths

Blended rate, keep your loan + HELOC

3.94%

Cash-out refinance rate on the whole balance

7.40%

  • Keep loan + HELOC, interest only$1,632.95
  • Cash-out refinance$2,284.14
Over 10 years
MeasureKeep loan + HELOCCash-out refi
Blended rate3.94%7.40%
Monthly payment now$1,633$2,284
Monthly payment in year 11$1,735$2,284
Interest over 10 years$114,492$229,900
Closing costs and fees$0$9,897
Total cost over 10 years$114,492$239,796
Still owed after 10 years$238,538$285,700
Blended rates match at a current rate of7.26%
Costs over 10 years match at a current rate of8.04%

Keeping your 3.00% mortgage and adding a $60,000 HELOC gives a blended rate of 3.94%, against 7.40% on a cash-out refinance. Over 10 years, keeping your loan costs about $114,492 in interest and fees, $125,305 less than the cash-out refinance. The cash-out refinance would cost less over 10 years only if your current rate were above about 8.04%.

See the HELOC payment in detail, check how much cash a refinance could free up, or read how to get home equity without refinancing.

These figures are estimates for planning only and are not an offer or a quote. Payments are principal and interest, before taxes and insurance. The HELOC is drawn in full on day one and its rate is held steady, although HELOC rates usually change. See our disclosures.

How this is calculated

Both paths start from the same numbers: what you owe now, its rate and years left, and the cash you need. The payment and loan-size math is the same as the cash-out refinance calculator.

  • Blended rate, keep your loan + HELOC

    (balance × current rate + cash × HELOC rate) ÷ (balance + cash)

    ($260,000 × 3.00% + $60,000 × 8.00%) ÷ $320,000 = 3.94%. The cash-out refinance has one rate on everything, 7.40% here.

  • Monthly payments

    L × i ÷ (1 − (1 + i)−n)

    Keep path: your current payment ($1,232.95 on $260,000 at 3.00% over 25 years) plus HELOC interest of $60,000 × 8.00% ÷ 12 = $400.00 while the line is interest only, then $501.86 a month to repay $60,000 over 20 years. Cash-out path: ($260,000 + $60,000) ÷ 0.97 = $329,897 with 3% closing costs added, at 7.40% over 30 years: $2,284.14.

  • Interest over the years you compare

    payment × months − (loan − balance still owed)

    Everything you pay in that time minus the part that paid down the loan. Over 10 years: $66,492 on the first mortgage plus $48,000 on the HELOC ($400 × 120), against $229,900 on the cash-out loan.

  • Where the answer flips

    (new rate × (balance + cash) − HELOC rate × cash) ÷ balance

    The current rate at which both blended rates match: (7.40% × $320,000 − 8.00% × $60,000) ÷ $260,000 = 7.26%, before closing costs. The cost break-even is the current rate at which interest, closing costs and fees over your years to compare come out equal, found by trying rates until the two totals match: 8.04% over 10 years here.

  • Fixed rates. Both mortgages are fixed. The HELOC rate is held at what you enter, although HELOC rates are usually variable and follow the prime rate.
  • The HELOC is drawn in full. The whole amount is borrowed on day one and only interest is paid during the interest-only years. Paying principal early lowers the HELOC’s cost.
  • Cost is interest plus fees. Principal you pay down is not a cost, so it is shown separately as what is still owed at the end of the years you compare.
  • No home value check. Lenders limit how much you can borrow against your home. See how much you could borrow at 80%, 85% and 90% limits.

Sources

  • Freddie Mac, Primary Mortgage Market Survey: 30-year fixed 7.40% and 15-year fixed 6.71%, week of October 15, 2026.
  • Federal Reserve, H.15 Selected Interest Rates: bank prime loan rate 7.00%, as of October 20, 2026.
  • Freddie Mac My Home, “Understanding the costs of refinancing” (accessed October 21, 2026).
  • CFPB, “What you should know about home equity lines of credit” (last reviewed April 3, 2024).

Last reviewed October 22, 2026.

Questions about blended rates

What is a blended mortgage rate?

It is the average rate on everything you owe against your home, weighted by each balance: first mortgage balance times its rate, plus HELOC balance times its rate, divided by the total. A $260,000 mortgage at 3.00% plus a $60,000 HELOC at 8.00% blends to 3.94%, well under a 7.40% cash-out refinance on the full $320,000.

How can I keep my low mortgage rate and still get cash?

Leave your first mortgage in place and borrow the cash with a second lien: a HELOC, which is a line of credit usually at a variable rate, or a home equity loan, which is a fixed amount at a fixed rate. Only the new money is borrowed at today's rates. A cash-out refinance pays off your mortgage and moves the whole balance to the new rate.

When does a cash-out refinance cost less than keeping my mortgage and adding a HELOC?

Usually when your current rate is close to or above today's rates, or when the cash you need is large compared with what you owe. This calculator shows two break-even points: the current rate where the two blended rates match, and the current rate where both paths cost the same over the years you choose, with closing costs and fees included.

Why can the HELOC path cost more later?

Many HELOCs are interest only during the draw period, often 10 years, and then switch to principal and interest. On $60,000 at 8.00%, that is $400 a month at first and $501.86 once a 20-year repayment starts. HELOC rates are also usually variable, so the payment can rise if the prime rate does.

Do I have to give my email or phone number to see results?

No. This calculator runs in your browser and shows every result as you type. Nothing you enter is sent to LenderMatch. If you later want offers from lenders, the HELOC form is a separate step you choose to take.

Keep reading

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Keep your rate and see what a HELOC would cost.

One short form, about 2 minutes, and lenders in your state reach out with their HELOC offers.

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