Home Equity Calculator

What this calculator is, and when to reach for it

Equity is the part of your home that is genuinely yours: what the property is worth, less what you still owe on it. It is the number people mean when they say a house has "made" them money, and it is also the number most commonly misunderstood, because equity on paper and money in hand are two very different things.

It grows from three directions at once. Your deposit is the equity you start with. Every payment converts a slice of debt into ownership, slowly at first and quickly later. And any rise in the property’s value adds to it without you doing anything at all. Those three sources behave quite differently, and knowing which one has been doing the work tells you how solid your position really is.

The distinction that matters most is between equity you own and equity you can access. Lenders will not let you borrow against all of it; they cap total borrowing at a percentage of the value, and the gap between that cap and your current balance is all that is realistically available. Owning 150,000 of equity does not mean 150,000 is waiting to be drawn.

Reach for this page when you are weighing whether to borrow against the property, when you are wondering whether mortgage insurance can be removed, before selling, or simply to see where a few years of payments and market movement have left you.

Equity is not proceeds, and not a windfall

If you sold today, you would not receive your equity. Selling costs money: agency fees, legal work, and sometimes tax, and in many markets those consume a meaningful share of the value. Whatever remains after the loan and the costs is what actually reaches you.

It is also worth resisting the idea that rising equity is income. A larger figure driven by house price growth does not improve your monthly position at all, and it is reversible in a way that repayment is not. Equity built by paying down debt is permanent; equity built by valuation is borrowed from the market and can be taken back.

The practical consequence is that a household whose equity is mostly market movement is more exposed than one whose equity came from repayment, even if the numbers look identical today.

Where to go next

Equity and loan to value describe the same position from opposite ends, and the ratio is the version lenders actually price against. Where more than one loan is secured on the property, the combined loan to value calculator gives the figure that governs what you can borrow.

To borrow against it, the home equity loan calculator covers a lump sum on a fixed schedule and the HELOC calculator covers a revolving credit line. To release cash by replacing the mortgage entirely, use the cash-out refinance calculator.

To build equity faster, the extra payment calculator shows what overpaying achieves, and the amortization calculator shows how much of it repayment will deliver on its own over the coming years.

How equity is worked out

The headline figure is a subtraction. What makes it useful is the second calculation, which tells you how much of it you could actually reach.

equity = value − secured debt   |   borrowable = (value × lender cap) − secured debt

value

the property’s current market value, as a lender would assess it

secured debt

every loan secured on the property, not just the first mortgage

lender cap

the maximum share of value a lender will allow across all borrowing

Every secured loan counts

A second charge, a home equity loan, or a credit line drawn against the property all reduce your equity exactly as the first mortgage does. Only the amount actually drawn counts on a credit line; an unused facility does not reduce equity, though a lender will often consider the limit rather than the balance when deciding what more to advance.

Unsecured debts do not belong here at all. A card balance or a personal loan affects what you can afford, but it is not secured on the property and does not touch your equity.

Why the borrowable figure is so much smaller

Lenders keep a margin between total borrowing and the property’s value so that a fall in prices does not leave the debt exposed. Caps commonly sit somewhere between 80% and 85% of value across all secured loans, and the tighter the cap, the less of your equity is reachable.

The effect is stark. On a property worth 450,000 with 296,716 owed, equity is 153,284 but an 85% cap leaves only 85,784 available, and an 80% cap leaves 63,284. Nothing is wrong with the equity figure; it simply is not what a lender is measuring.

Valuation is the weak point

Everything on this page depends on a value that nobody can pin down precisely. Your own estimate, a listing site’s figure, and a lender’s valuation will disagree, and the only one with any authority in a transaction is the lender’s.

That uncertainty is asymmetric in its consequences. Overestimating value inflates your equity, inflates what you think you can borrow, and produces plans that collapse when a valuer visits. Being deliberately conservative costs nothing and prevents that.

When equity turns negative

If the secured debt exceeds the value, equity is negative and the property is commonly described as underwater. This calculator reports negative figures rather than treating them as an error, because pretending otherwise would be unhelpful.

Negative equity is not a default, and nothing happens while payments continue. What it does is close off borrowing against the property and make selling difficult, since completing would require finding the shortfall in cash. Continued repayment and time are the ordinary remedies.

What this page assumes

This calculator subtracts outstanding secured debt from property value, then provides equity and secured-debt ratios.

It does not calculate lender limits, sale proceeds, taxes, fees, or approvals.

Worked examples, step by step

Take a property now valued at 450,000 with 296,716.44 outstanding on the mortgage — roughly the position of someone ten years into a 350,000 loan at 6.5% whose home has appreciated.

What is owned, and what is reachable

The household owns 153,284 of equity, a genuinely strong position. But depending on the cap applied, only 85,784 or 63,284 is actually available to borrow. The difference between what you own and what you can reach is the single most common surprise on this subject.

Note too that a 5% fall in value to 427,500 would reduce equity to 130,784 and the 80% borrowing capacity to 45,284 — a 28% drop in available funds from a 5% market movement. Borrowing capacity is far more volatile than equity itself.

Where the equity came from

Of that 153,284, only 53,284 came from ten years of repayment on the original 350,000 loan. The remaining 100,000 is appreciation, which arrived without a single extra payment and could depart the same way.

This is the split worth knowing about your own position. Two households can both hold 150,000 of equity, one having repaid it and one having watched the market deliver it, and they are not equally secure. The first cannot lose it; the second can.

The vocabulary, on and around this page

Home equity

The property’s value less every loan secured on it. It is the portion you own outright, expressed as an amount rather than a ratio.

Secured debt

Any borrowing that uses the property as security, including the first mortgage, second charges, and drawn credit lines.

Borrowable equity

What a lender would actually advance: the cap applied to the value, less what you already owe. Always less than the equity you own.

Lender cap

The maximum share of a property’s value a lender will allow across all secured borrowing, commonly between 80% and 85%.

Loan to value

Secured debt as a percentage of value. It is the same position as equity, expressed the way lenders price against.

Combined loan to value

The ratio counting every secured loan together. This is the figure that governs additional borrowing.

Negative equity

Owing more than the property is worth. It blocks borrowing against the property and complicates selling, but is not a default.

Appreciation

A rise in property value. It builds equity without payments, and unlike repayment it can reverse.

Valuation

A lender’s assessment of value. It is the only figure with authority in a transaction, regardless of other estimates.

Automated valuation

An estimate produced from market data rather than an inspection. Some lenders accept it; others require a surveyor.

Net proceeds

What actually reaches you on a sale: value less the loan and less selling costs. Always less than equity.

Selling costs

Agency fees, legal work, and any transaction taxes on a sale. They consume a meaningful share of equity when you exit.

Home equity loan

A lump sum borrowed against equity and repaid on a fixed schedule, secured as a second charge on the property.

Home equity line of credit

A revolving facility secured on the property. Only the amount drawn reduces equity, though lenders may assess the full limit.

Cash-out refinance

Replacing the mortgage with a larger one and taking the difference in cash. It converts equity to cash and raises the loan to value.

Second charge

A loan ranking behind the first mortgage against the property. It reduces equity and raises the combined ratio.

Mortgage insurance

A premium required below certain equity levels. Reaching roughly a fifth of value in equity is commonly what removes it.

Amortization

The repayment schedule. It converts debt into equity slowly in the early years and rapidly in the later ones.

Paper equity

Equity that exists in a valuation but has not been realised or borrowed against. It can fall as easily as it rose.

Reserve margin

The buffer lenders keep between total borrowing and value, which is why borrowable equity is always less than equity owned.

Common mistakes, and what this page will not do

• Assuming equity is available to borrow. Lenders cap total borrowing at a share of value. On the worked example, 153,284 of equity yields only 63,284 to 85,784 of borrowing capacity.
• Treating equity as sale proceeds. Agency fees, legal costs, and any transaction tax come out first. What reaches you on a sale is always less than your equity.
• Using an optimistic value. Only a lender’s valuation counts in a transaction. Overestimating inflates both equity and expectations, and plans built on it collapse at survey.
• Forgetting a second loan or credit line. Every secured borrowing reduces equity. Leaving out a second charge or a drawn credit line overstates your position substantially.
• Confusing appreciation with repayment. Equity from rising prices can reverse; equity from paying down debt cannot. Two identical figures do not represent identical security.
• Expecting mortgage insurance to fall away automatically. Reaching the equity threshold rarely removes it by itself. It usually has to be requested, often with a fresh valuation.
• Overlooking how volatile borrowing capacity is. A 5% fall in value cut available borrowing by 28% in the example. Capacity moves far faster than equity does.
• Counting unsecured debts here. Cards and personal loans affect affordability but are not secured on the property and do not reduce equity.
• Treating rising equity as income. A higher valuation changes nothing about your monthly position. Spending against it converts a paper gain into a real debt.

What this calculator leaves out: This calculator does not produce or verify a valuation, calculate selling costs or taxes, determine what any lender would advance, model mortgage insurance removal, or account for unsecured debts. It subtracts the secured debt you enter from the value you enter, and reports negative equity where it arises.

Frequently asked questions