Estimates, comps, equity math, and the step that turns a number into something you can actually act on. A practical guide to knowing your home’s value.
Knowing what your home is worth can feel like hitting a moving target — values shift with the market, and the number you heard last year almost certainly doesn’t hold today. Online home value estimators (also called Automated Valuation Models, or AVMs) try to solve this by pulling together real-time data to generate a quick snapshot of what your home might sell for right now.
Here’s how they actually work under the hood:
Public records — county assessor data on square footage, lot size, bedroom and bathroom count, and your property’s sale history forms the baseline
Comparable sales — recently sold homes near yours with similar characteristics are the most influential input; the closer the comps, the more accurate the estimate
Local market trends — current inventory levels, average days on market, price movement, and seasonal demand patterns all get factored in
Algorithm weighting — each platform weights these inputs differently, which is why Zillow, Redfin, and Realtor.com often produce different estimates for the same address
An estimate is a starting point — not a sale price. Online estimators can’t see inside your home. They don’t know about your renovated kitchen, the roof you replaced last year, or the water stain in the basement. Median error rates run 6–7.5% for off-market homes — on a $400,000 home, that’s a potential $28,000+ swing in either direction.
Best practice: Check two or three estimators and average the results. Then request a free CMA from a local agent or a cash offer from ARS to get a number grounded in professional judgment rather than an algorithm.
Section 02
What goes into your estimate
Every data point the algorithm uses falls into one of these categories. Understanding them helps you identify where an estimate might be over or understating your home’s value.
Location & neighborhood
School district quality, proximity to amenities, crime rates, and neighborhood trajectory. The single biggest driver of value — and the one you can’t change.
Square footage & layout
Total finished living space, bedroom and bathroom count, and how functional the floor plan is. Open layouts command premiums over choppy, disconnected rooms.
Age & condition
How old the home is and the state of major systems — roof, HVAC, plumbing, electrical. Deferred maintenance signals risk to buyers and suppresses value.
Recent upgrades
Kitchen and bath refreshes, new systems, energy-efficient windows. Estimators may lag on capturing these until public records update — sometimes months later.
Comparable sales
What similar homes nearby sold for in the past 60–90 days. The most influential input — and the one that changes fastest as the market moves.
Market conditions
Inventory levels, interest rates, buyer demand, and seasonal patterns. A home worth $400,000 in a buyer’s market might command $430,000 in a seller’s market.
Section 03
How to find real estate comps yourself
You don’t need a license to research comparable sales. Here’s a step-by-step approach that gives you a real sense of where your home stands in the current market.
1
Search recently sold listings online
On Zillow or Redfin, filter for “sold” listings in your area. Look for homes that closed within the past three to six months. Pay attention to actual sale prices, not list prices — they’re often different.
2
Stay within one mile
Focus on properties within a close radius. The further away a comp is, the less relevant it is — market conditions, school zones, and neighborhood quality can shift dramatically from one block to the next.
3
Match key characteristics
Look for similar square footage (within 10–15%), same bedroom and bathroom count, comparable lot size, and similar age and condition. A 4-bed/2-bath built in 2005 is a good comp for your 4-bed/2-bath built in 2007. A 2-bedroom condo down the street is not.
4
Adjust for differences
No two homes are identical. If a comp has a renovated kitchen and yours doesn’t, adjust the price downward mentally. If your home has a larger lot or an extra bathroom, adjust upward. These adjustments are rough, but they move you toward a more realistic range.
5
Cross-check with public records
County assessor and recorder websites publish official sale prices and property details for free. Use these to verify what you’re seeing on real estate platforms and catch any discrepancies.
Watch out for objectivity bias. Most homeowners overestimate their home’s condition and the value of their upgrades. That kitchen remodel you spent $55,000 on may add only a fraction of that in market value. Try to evaluate your home the way a buyer would — or ask a trusted third party to walk through it with fresh eyes.
Section 04
Calculating your home equity
Home equity is the portion of your property you actually own — the difference between what it’s worth today and what you still owe on your mortgage. It’s one of the most important numbers in your personal financial picture.
Current Home Value
−
Remaining Mortgage Balance
=
Your Equity
For example: if your home is worth $420,000 and you owe $255,000, you have $165,000 in equity. That’s money you’ve built up through mortgage payments, appreciation, and improvements — and it’s money you receive at closing when you sell.
Knowing your equity helps you understand:
Your selling position — whether you can comfortably cover closing costs, pay off the mortgage, and still walk away with cash
Refinancing options — most lenders require at least 20% equity to refinance without PMI
Borrowing power — home equity loans and HELOCs let you tap built-up equity for other financial goals
Net worth — for most homeowners, their home equity is their single largest asset
Use the equity calculator at the top of this page for a rough estimate, then use our Home Sale Calculator to see what you’d actually net after fees, commissions, and closing costs in a traditional sale vs. a cash sale.
Section 05
Online estimate vs. professional appraisal
Both give you a sense of what your home is worth, but they serve different purposes and carry very different weight.
Feature
Online Estimator
Professional Appraisal
Cost
Free
$300–$600
Speed
Instant
Several days
Physical inspection
No
Yes — certified
Accuracy
6–7.5% error rate
Most reliable available
Captures renovations
Delayed (public records)
Yes — direct inspection
Best for
Research & tracking
Mortgages, legal matters, selling
For most homeowners just keeping tabs on their equity, a free online estimate is sufficient. When you’re actively selling, refinancing, or making major financial decisions based on your home’s value, a professional appraisal or a real cash offer gives you a number you can actually act on.
Section 06
What to do once you have an estimate
An estimate is the beginning of a decision, not the end. Here’s how to use it productively depending on where you are in your journey.
A
If you’re just tracking equity
Check two or three estimators, average the results, and note the date. Do this every few months to stay informed about how your market is moving. The trend over time matters as much as any single snapshot.
B
If you’re thinking about selling
Use the estimate as a ballpark, then request a free CMA from two or three local agents to refine the number. Run the Home Sale Calculator to see what you’d actually net after fees. Consider a cash offer from ARS alongside the traditional route so you’re comparing real options, not estimates.
C
If you need a certified number
Refinancing, estate settlement, divorce proceedings, or contesting a tax assessment all require a licensed appraisal. An online estimate carries no legal or financial weight in these contexts — only a certified appraiser’s report does.
D
If you want to skip the whole process
ARS can turn an estimate into a real, no-obligation cash offer within 24–48 hours. No staging. No showings. No months of uncertainty. You get a concrete number you can accept, reject, or compare against other options — with zero pressure.
Section 07
Frequently asked questions
How often should I check my home’s estimated value?
A few times per year is sufficient for most homeowners tracking equity. After major market shifts, significant local news (new development, a large employer arriving or leaving), or if you’ve made substantial improvements, it’s worth checking again. If you’re actively considering a sale, check monthly and get a CMA before listing.
Why does my home value estimate differ from my tax assessment?
Tax assessments are calculated by county assessors for property tax purposes, using their own schedule and methodology — not current market data. They often lag the market significantly and can be higher or lower than what your home would actually sell for. Never use your tax assessment to set a list price or make financial decisions about your home.
My online estimate seems inaccurate. What should I do?
First, check that the property details are correct — many tools let you edit square footage, bedroom count, and recent improvements. If the basics are right and the estimate still seems off, it likely reflects a data limitation: few recent comps nearby, a unique property, or recent renovations not yet in public records. Request a CMA from a local agent or a cash offer from ARS for a more grounded number.
Do renovations update automatically in online estimators?
No — and this is one of the biggest limitations of AVMs. Estimators pull from public records, which are updated on the county’s schedule. A kitchen renovation you completed six months ago may not show up for months. A professional appraiser or cash buyer who visits the property will capture it immediately.
Can I turn my estimate into a real offer?
Yes. Submit your address to ARS and we’ll evaluate your specific property — condition, comps, current market — and give you a real cash offer, typically within 24–48 hours. Unlike an estimate, it’s a number you can actually accept. No obligation, no pressure, no fees.
How is a cash offer different from an online estimate?
An online estimate is generated by an algorithm using public data — it’s an educated guess. A cash offer from ARS is a real offer from a real buyer who has evaluated your specific property. You can accept it, reject it, or use it to benchmark other offers. The key difference: an estimate is information; a cash offer is action.
From estimate to offer
Stop guessing. Get your real number.
Submit your address and ARS will give you a no-obligation cash offer — a real, concrete number based on your actual property. Not an algorithm. Not an estimate. Something you can act on.