Mortgage Calculators

Blended Rate Mortgage Calculator

If you carry a first mortgage and a second loan or HELOC, your true cost is the blended rate. Find the weighted average across both.

Inputs

First mortgage balance

First mortgage rate

Second loan / HELOC balance

Second loan rate

Years remaining

Estimates only. Change any value to recalculate instantly.

Blended interest rate 6.395% on $285,000 of combined mortgage debt

Combined balance $285,000

Blended rate 6.395%

Monthly interest $1,518.75

Rate spread 6.00% / 8.50%

Debt by balance

First (6.0%) $240k
Second (8.5%) $45k

Combined balance Balance

Your blended rate of 6.395% is the weighted average across both loans. It is the figure to compare against a single cash-out refinance — refinancing only makes sense if the new rate beats this blend.

Combined amortization at the blended rateView table

Year	Principal	Interest	Balance
1	$4,781	$18,086	$280,219
2	$5,096	$17,772	$275,123
3	$5,432	$17,436	$269,691
4	$5,789	$17,078	$263,902
5	$6,171	$16,697	$257,731
6	$6,577	$16,291	$251,154
7	$7,010	$15,858	$244,144
8	$7,472	$15,396	$236,673
9	$7,964	$14,904	$228,709
10	$8,488	$14,379	$220,221
11	$9,047	$13,820	$211,173
12	$9,643	$13,225	$201,530
13	$10,278	$12,590	$191,252
14	$10,955	$11,913	$180,297
15	$11,676	$11,191	$168,621
16	$12,445	$10,422	$156,175
17	$13,265	$9,603	$142,911
18	$14,139	$8,729	$128,772
19	$15,070	$7,798	$113,702
20	$16,062	$6,806	$97,640
21	$17,120	$5,748	$80,521
22	$18,247	$4,620	$62,273
23	$19,449	$3,419	$42,825
24	$20,730	$2,138	$22,095
25	$22,095	$773	$0

How this calculator works

This calculator runs entirely in your browser — nothing you enter is sent anywhere, and there is no sign-up. Change any input and the result, breakdown, and schedule update instantly.

Rate and cost fields are pre-filled with current benchmarks (Federal Reserve / Freddie Mac via FRED (St. Louis Fed)), so your first result is already realistic — replace them with your own quote to see your numbers. To weigh one option against another, use the loan comparison calculator.

30-year fixed mortgage rate, 2019–2026

Source: Freddie Mac PMMS via FRED. Annual averages; latest weekly reading shown.

Common questions

Is this calculator free, and do I need to sign up?

Yes and no — it is completely free and asks for no account or personal details. Every calculation happens in your browser, so nothing you type is stored or sent to us.

How accurate are the results?

The math is exact for the inputs you give it, but the defaults are national benchmarks — your real rate, fees, taxes, and insurance will differ. Treat the result as a close estimate to refine with a real quote.