Last updated: May 21, 2026

How to Calculate Your Home Equity

The Basic Home Equity Formula

Calculating your home equity is straightforward: take your home’s current market value and subtract everything you owe on it. This includes your primary mortgage balance, any existing home equity loans, HELOCs, and other liens against the property. The result is your total home equity — the portion of your home that you actually own.

For example, if your home is currently worth $450,000 and you have a primary mortgage balance of $280,000 and no other liens, your home equity is $170,000. That represents 37.8% of your home’s value. If you also have a HELOC with a $30,000 outstanding balance, your equity drops to $140,000 (31.1% of home value).

It’s important to use current values, not original values. Your home’s market value has likely changed since you purchased it, and your mortgage balance has decreased with each payment. Both factors work in your favor over time — home values generally appreciate while your mortgage balance shrinks, steadily increasing your equity position.

How to Determine Your Home’s Current Value

The most critical and challenging part of calculating home equity is determining your home’s current market value. There are several methods, ranging from free online estimates to paid professional appraisals, each with different levels of accuracy.

Online valuation tools (Zillow’s Zestimate, Redfin Estimate, Realtor.com) provide instant estimates using algorithms that analyze recent sales, tax assessments, and property characteristics. These are convenient but can be off by 5% to 15% in either direction. They work best in neighborhoods with many recent comparable sales and less well in rural areas or unique properties.

A Comparative Market Analysis (CMA) from a real estate agent is more accurate. Agents analyze 3 to 6 recent sales of similar homes in your area, adjusting for differences in size, condition, features, and location. CMAs are typically free (agents provide them hoping to earn your business) and are accurate within 3% to 7%. For the most accurate value, a professional appraisal ($300 to $600) conducted by a licensed appraiser provides a detailed valuation that lenders actually rely on for lending decisions.

Your Borrowable Equity vs. Total Equity

There’s an important distinction between your total home equity and how much you can actually borrow against it. Lenders don’t let you borrow 100% of your equity — they require you to maintain a cushion to protect against potential home value declines. Most lenders cap your combined loan-to-value (CLTV) ratio at 80% to 85%.

Here’s how borrowable equity works: If your home is worth $400,000, an 80% CLTV limit means you can have no more than $320,000 in total mortgage debt (including the new loan). If your current mortgage balance is $250,000, your maximum borrowable equity is $70,000 ($320,000 – $250,000). With an 85% CLTV limit, you could borrow up to $90,000 ($340,000 – $250,000).

Some lenders offer up to 90% or even 100% CLTV for well-qualified borrowers, but these come with higher interest rates (typically 0.5% to 1.5% more) and stricter credit requirements (often 740+ credit score). For most borrowers, planning around the 80% CLTV standard provides the best combination of access and favorable rates.

How Equity Builds Over Time

Home equity grows through two mechanisms: paying down your mortgage principal and home value appreciation. Both work simultaneously, and understanding their relative contributions helps you project your future equity position and borrowing capacity.

Mortgage principal reduction is the “forced savings” component. Each monthly mortgage payment includes both interest and principal, with the principal portion gradually reducing your balance. On a $300,000 mortgage at 6.5% over 30 years, your balance drops to approximately $274,000 after 5 years, $238,000 after 10 years, and $188,000 after 15 years. That’s $112,000 in equity built purely through payments by the halfway point.

Home appreciation is the market-driven component and has been particularly strong in recent years. The national average home appreciation rate is approximately 3% to 5% per year, though this varies dramatically by market. A home purchased for $350,000 with 3.5% annual appreciation would be worth approximately $415,000 after 5 years and $492,000 after 10 years. Combined with mortgage paydown, a homeowner who started with 20% down ($70,000 in equity) could have $200,000+ in equity after 10 years.

• Year 1: Equity grows slowly — most of your mortgage payment goes to interest.
• Years 2-5: Equity builds from both principal payments and early appreciation.
• Years 5-10: Acceleration phase — principal payments increase while appreciation compounds.
• Years 10-20: Significant equity — the majority of each payment now goes to principal.
• Year 20+: Most of the home’s value is equity, with a small remaining mortgage balance.

Factors That Increase or Decrease Your Equity

Several factors beyond regular mortgage payments and market appreciation affect your home equity position. Home improvements that increase your property’s value are one of the most direct ways to build equity. A kitchen remodel (averaging $25,000 to $50,000) typically recoups 60% to 80% of its cost in added home value. A bathroom addition ($20,000 to $40,000) recoups 50% to 70%.

On the negative side, declining property values can erode equity quickly. During the 2008-2012 housing downturn, many homeowners saw 20% to 40% value declines that wiped out their equity entirely. While that level of decline is unlikely in 2026, localized market corrections of 5% to 10% are possible in overheated markets. Taking on additional debt against the property (second mortgages, HELOCs) also reduces your equity position.

Deferred maintenance can quietly erode equity by reducing your home’s value relative to comparable properties. A roof that needs replacement, outdated electrical systems, foundation issues, or neglected landscaping can reduce your home’s value by 10% to 20% compared to well-maintained comparable homes. Regular maintenance preserves equity even if it doesn’t feel like an investment.

Last updated: March 2026. Rates and requirements are subject to change. Always verify current terms with lenders directly.

Reviewed by Priya Iyer, CFA®. Priya Iyer, CFA®, is a chartered financial analyst with 14 years of experience in self-directed retirement vehicles, alternative assets, and residential mortgage products. Last reviewed May 2026.