Free tool · Updated October 2026

Home Equity Calculator for Solar (2026)

Some owners pay for solar with a home equity line of credit (HELOC) or a fixed home equity loan. Enter your home value, mortgage and the limit in your lender's terms to see how much room it leaves, then compare the two products. We are not a lender: every rate, fee and limit on this page is an example you change.

Updated October 2026No federal homeowner credit countedNo lender offers, no credit check

Short answer

Equity is what your home is worth minus what you still owe on the mortgage. A lender will lend only up to a share of the home's value, counting the mortgage and the new loan together (the combined loan-to-value, CLTV). That share is set by each lender, so you type in the one from the written terms and the calculator shows the room it leaves.

The two products behave differently. A home equity loan is a lump sum with a level payment, normally at a fixed rate. A HELOC is a line of credit with a variable rate and, often, a draw period in which payments can be interest-only, then a repayment period in which the payment jumps. Both are secured by your home: if you cannot pay, the lender can foreclose. That is why the page shows what the payment becomes if the rate rises.

Enter your figures below, then see the comparison and the rate stress test.

These are not offers. Fields marked EXAMPLE are placeholders, not market rates, lender limits or terms. Replace them with the figures in a lender's written terms.

1. Your home and the amount

Use a recent appraisal or a realistic estimate. A lender will order its own valuation.

EXAMPLE: use your own estimate
EXAMPLE: 0 if you have no mortgage. Include any other loan secured on the home.
EXAMPLE limit, not a rule. Lenders set their own: use the one in their written terms.
EXAMPLE: the part of the solar price you want to borrow

2. A HELOC (line of credit)

Variable rate: prime plus the lender's margin. The calculator assumes the whole amount is drawn at the start.

EXAMPLE: 7.00, the bank prime rate on 7 Oct 2026 (Federal Reserve H.15). It changes: check the current value.
EXAMPLE margin. We have not verified a typical 2026 margin; use your lender's terms.
EXAMPLE: payments here are interest only. Some plans differ.
EXAMPLE: then principal and interest. Some plans demand the balance when the draw ends.
EXAMPLE: 0 if none. Application, appraisal, title and similar fees.
EXAMPLE: 0 if none. Charged in every draw and repayment year.

3. A fixed home equity loan

A lump sum with a level monthly payment. Use the rate and term from the lender's written terms.

EXAMPLE rate, not a market rate or an offer. Use your lender's terms.
EXAMPLE term.
EXAMPLE: 0 if none.
Example inputs

Calculating... of room under your limit

Your homeAmount

HELOC and home equity loan, side by side

Same amount. The HELOC rate is held at today's example rate for the whole period, which a variable rate will not do: see the stress test.

HELOCHome equity loan

If the HELOC rate rises

Same line, same balance. Only the rate moves up. These rows are what-ifs, not predictions.

RatePayment, draw periodPayment, repayment period

    Planning arithmetic only. Not a loan offer, a quote, tax advice or a credit decision. SolarNiverse is not a lender. Your lender's written terms decide your real limit, rate and payment. How this is calculated.

    What to know before borrowing against your home

    • Your home is the collateral. An unsecured solar loan puts your credit at risk; a home equity loan or HELOC puts the house at risk. A lender can foreclose if you stop paying.
    • The HELOC payment changes twice. The rate can move with prime, and when the draw period ends the payment typically starts to include principal, so it can jump. The table shows both.
    • Fees are real. A lender may charge application, origination, appraisal, title, closing, yearly and early-cancellation fees. We have not verified typical amounts, so enter yours.
    • Compare with the other ways to pay. A solar loan is priced differently, and a lease or PPA uses no loan at all. See the financing options guide, the payment calculator and the lease vs buy calculator.

    Three days to change your mind. For many loans secured by your main home, federal rules give you a right to cancel within three business days of opening the account or signing. It is separate from any right to cancel the solar installation contract itself, and there are exceptions, so ask your lender and your installer for their cancellation terms in writing.

    Taxes: the credit and the interest

    The Section 25D homeowner credit is not allowed for expenditures made after December 31, 2025. For solar, an expenditure counts as made when the installation is finished, so paying earlier does not help if the system is completed later. This calculator therefore counts no federal credit.

    Interest on a home equity loan or line of credit is deductible only if you itemize, the debt is secured by the home it improves, and the money is used to buy, build or substantially improve that home, within the overall debt limits (IRS Publication 936). Whether a particular solar project meets that test is a question for a tax professional, so the calculator subtracts no tax saving.

    How the calculator works

    • Equity is home value minus mortgage balance. Room is home value times the limit you entered, minus the mortgage balance, and never below zero.
    • CLTV after borrowing is (mortgage + amount) divided by home value. The page says whether that is within the limit you typed in, and by how much it is over. It cannot tell you whether a lender will lend to you: credit, income, other debts and the lender's own rules all matter, and we do not check any of them.
    • HELOC. Rate = prime + margin. During the draw period the payment is the balance times the rate divided by 12. In the repayment period it is the standard level payment over the years you chose, at the same rate. Total cost is the interest in both periods plus the fees.
    • Home equity loan. The standard level-payment formula at the rate and term you enter. Total cost is the interest plus the closing costs.
    • The calculator does not know about your credit, a rate that changes over time, rate caps, minimum draws, prepayment penalties, or taxes.

    Before you sign, ask for: the rate and annual percentage rate (APR), whether the rate can change and any cap, every fee and when it is charged, what the payment is after the draw period, whether you can repay early without a penalty, and what happens to the line if your home value falls.

    Frequently asked questions

    What is combined loan-to-value?

    Combined loan-to-value (CLTV) is your mortgage balance plus the new loan, divided by the value of the home. Lenders set their own limits and they differ, so the calculator asks you to enter the limit from the lender's written terms and shows the room it leaves. Any number it starts with is an example.

    What is the difference between a HELOC and a home equity loan?

    A home equity loan pays out a lump sum at once and is usually repaid in level payments, normally at a fixed rate. A HELOC is a line of credit you draw on, usually with a variable rate, often with a draw period where payments can be interest-only, followed by a repayment period. Both are secured by your home.

    What happens if I cannot repay a loan secured by my home?

    The lender can foreclose on the home. That risk is the main difference from an unsecured solar loan, and it is why the rate, the payment after the draw period ends and the stress test matter.

    Is home equity loan interest tax deductible?

    Only in limited cases. Under IRS Publication 936, interest on a home equity loan or line of credit is deductible only if you itemize and the money is used to buy, build or substantially improve the home that secures the loan, within the overall debt limits. Whether a solar project fits is a question for a tax professional. The calculator does not subtract any tax saving.

    Is there a federal tax credit for solar I pay for with a home equity loan?

    Not for homeowners who buy their system. The Section 25D credit is not allowed for expenditures made after December 31, 2025, and for solar that means installation completed after that date. The calculator counts no federal credit.

    Is the prime rate on this page my rate?

    No. The prime rate is the index many variable-rate lines are priced from; your rate is the prime rate plus the margin in your lender's written terms. The prime rate changes, so check the current value. The page starts with 7.00%, the Federal Reserve's weekly figure for 7 October 2026, as an example.

    Are the figures on this page a loan offer?

    No. SolarNiverse is not a lender, does not make or arrange loans and does not check your credit. The results are arithmetic on the numbers you type in.