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HELOC calculator

Size a home equity line of credit. From your home value and mortgage balance it shows the equity you can borrow against at a target combined loan-to-value, then computes the draw-period and repayment-period payments — interest-only or full principal-and-interest during the draw — plus the total interest.

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Enter Home value, Current mortgage balance, Max combined loan-to-value, HELOC amount drawn, Interest rate (APR), Draw period (years), Repayment period (years), Draw-period payment and the HELOC calculator works out Available equity, Draw-period payment, Repayment-period payment, Total interest straight away. For instance, with Home value = $500,000.00, Current mortgage balance = $250,000.00, Max combined loan-to-value = 85%, HELOC amount drawn = $100,000.00, Interest rate (APR) = 8.5%, Draw period (years) = 10, Repayment period (years) = 20 and Draw-period payment = Interest-only it returns Available equity = $175,000.00, Draw-period payment = $708.33 and Repayment-period payment = $867.82.

How to use it

  1. Enter your values: Home value, Current mortgage balance, Max combined loan-to-value, HELOC amount drawn, Interest rate (APR), Draw period (years), Repayment period (years), Draw-period payment.
  2. Read the result instantly: Available equity, Draw-period payment, Repayment-period payment, Total interest.

Frequently asked questions

How does the HELOC calculator work?

It takes Home value, Current mortgage balance, Max combined loan-to-value, HELOC amount drawn, Interest rate (APR), Draw period (years), Repayment period (years) and Draw-period payment and derives Available equity, Draw-period payment, Repayment-period payment and Total interest from them. The calculation is live as you type, so the result updates on every change.

Which values does the calculator ask for?

8 values: Home value ($), Current mortgage balance ($), Max combined loan-to-value (%), HELOC amount drawn ($), Interest rate (APR) (%), Draw period (years), Repayment period (years) and Draw-period payment. Nothing else is required — no account, no file upload.

What does a typical calculation look like?

With Home value = $500,000.00, Current mortgage balance = $250,000.00, Max combined loan-to-value = 85%, HELOC amount drawn = $100,000.00, Interest rate (APR) = 8.5%, Draw period (years) = 10, Repayment period (years) = 20 and Draw-period payment = Interest-only, the calculator returns Available equity = $175,000.00, Draw-period payment = $708.33 and Repayment-period payment = $867.82. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

How much does the result change with different inputs?

It moves a lot. Using Home value = $1,000,000.00, Current mortgage balance = $500,000.00, Max combined loan-to-value = 94%, HELOC amount drawn = $200,000.00, Interest rate (APR) = 9.4%, Draw period (years) = 20, Repayment period (years) = 40 and Draw-period payment = Principal & interest instead, Available equity goes from $175,000.00 to $440,000.00 — which is why it is worth testing a few scenarios rather than trusting a single figure.

Which “Draw-period payment” option should I choose?

You can pick between « Interest-only » and « Principal & interest ». Each one changes what the calculator works out, so switch and compare — the default is « Interest-only ».

Which units should I enter the values in?

Enter Max combined loan-to-value % and Interest rate (APR) %.

What does it give for smaller values?

Scaled down to Home value = $250,000.00, Current mortgage balance = $125,000.00, Max combined loan-to-value = 77%, HELOC amount drawn = $50,000.00, Interest rate (APR) = 7.7%, Draw period (years) = 5, Repayment period (years) = 10 and Draw-period payment = Interest-only, Available equity comes out at $67,500.00. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Before making an offer: what the bank will lend, what the purchase costs on top of the price, and how much deposit closes the gap.

What is the most common mistake?

Budgeting for the price and forgetting the acquisition costs. Notary fees, transfer duty and registration add between 2% and 15% depending on the country — enough to sink an offer.

How accurate is it, and what are the limits?

Estimate only, not financial advice. Real rates, fees, taxes and lender terms vary — confirm with your lender.

Further reading

All guides →
ExplainerA HELOC Is Two Loans Wearing One NameA draw period and a repayment period behave completely differently. On a $100,000 line at 8 percent the payment goes from $666.67 to $955.65 overnight — and to $1,200.17 if the rate has reached 12 percent. Ten years of interest-only payments leave the balance exactly where it started.ComparisonComparing Two Mortgage Offers ProperlyThe rate is not the comparison. Over a five-year holding period the 6.25 percent offer with $2,000 of fees beats the 5.875 percent offer with $12,000 by $2,485.73; the crossover falls at month 80, not at the month 103 the simple payback suggests.ExplainerRecasting a Mortgage Is the Option Nobody MentionsThe same $60,000 lump sum, three ways. Recasting drops the payment by $405.12 and saves $61,537 of interest. Keeping the payment saves $174,359. Refinancing does something else again — and which one wins depends on a question nobody asks.ExplainerA Construction Loan Is Not a MortgageFunds arrive in stages and interest accrues only on what has been drawn. On a $400,000 facility at 8.5 percent over twelve months, that is $18,062.50 rather than the $34,000 the headline rate implies — 53.13 percent of it.ExplainerFinancing Land Is the Hardest Money to BorrowLarger deposit, shorter term, higher rate, and a balloon at year five. On the same $120,000 plot, the land loan costs $768.10 a month against a mortgage's $606.79 — and demands $18,000 more at closing.How-toHow to Read an Amortization ScheduleUnderstand an amortization schedule row by row: how each payment splits into principal and interest, and why early payments are mostly interest.
HELOC calculator — OneKitly