Price Per Square Foot Calculator
The house & the comps
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- United States — state and local practice
- Scope and limitations
- Educational estimate only. U.S. real estate costs are local: property tax rates, transfer and recording taxes, title practice, who customarily pays which closing cost, and landlord-tenant rules all change by state and often by county or city. Agent commission is negotiable and, since the 2024 NAR settlement, buyer-agent compensation is negotiated separately rather than assumed. Only a lender's Loan Estimate, a title company's fee sheet or a signed contract binds a number.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter the asking price and the square footage of the home you are looking at.
- 02
Enter at least one comparable sale — a similar home nearby that recently closed — with its price and square footage.
- 03
Open Advanced options to add two more comps. Blank ones are ignored rather than averaged in as zero.
- 04
Read your price per square foot against the comp average.
- 05
Check the implied value and the premium. A few percent either way is noise; twenty percent is a conversation.
Formula
The subject's price per square foot is its price divided by its square footage, rendered as a dash rather than a division by zero when no area is entered. Comps are collected as price and area pairs, and any pair with no square footage is dropped before averaging — averaging a blank comp in as zero is exactly the bug this guard prevents, since every field on this site opens at zero. The comp average is the total price of the surviving comps divided by their total square footage, which is the dollar-weighted figure an appraiser uses rather than the mean of the individual per-foot numbers. The implied value is that average times the subject's square footage, and the premium is how far the asking price sits above or below it. When no comp survives, every comp output renders as a dash and the page asks for one.
Example
A house asking $425,000 for 1,900 square feet, against three comps: $410,000 for 1,850, $455,000 for 2,050 and $389,000 for 1,720. Step 1 — The subject: $425,000 / 1,900 = $223.68 a square foot. Step 2 — The comps, dollar-weighted: ($410,000 + $455,000 + $389,000) / (1,850 + 2,050 + 1,720) = $1,254,000 / 5,620 = $223.13 a square foot. Step 3 — Implied value: $223.13 x 1,900 = $423,950. Step 4 — Premium: $425,000 against $423,950 is +0.2%, or $1,050 over. That is as close to fairly priced as this metric can tell you — the asking price is within a quarter of a percent of what the comps support. Worth noting what the weighting did. The three individual figures are $221.62, $221.95 and $226.16, and their simple mean is $223.24 — close here because the comps are similar in size. Add a 900-square-foot cottage at $260 a foot and the simple mean jumps while the weighted figure barely moves, which is exactly why appraisers weight by size.
Definitions
- Price per square foot
- Sale price divided by finished living area. A comparison metric, not a valuation.
- Comparable sale
- A similar home nearby that recently closed. The basis of every residential valuation.
- Dollar-weighted average
- Total comp price over total comp square footage. How an appraiser blends comps.
- Implied value
- The comp average per foot times the subject's square footage.
- Premium or discount
- How far the asking price sits above or below the implied value, as a percentage.
- Above-grade living area
- Finished space at or above ground level. The standard square footage measure; basements are counted separately.
- Adjustment
- An appraiser's line-item correction to a comp for differences in condition, lot, garage or updates.
- Subject property
- The home being valued, as against the comps it is measured with.
- Tract housing
- A subdivision of similar homes, where this metric works best.
- Construction cost per foot
- What it costs to build, excluding land. A different number from sale price per foot.
- Fixed cost spreading
- Why small homes cost more per foot — kitchens and roofs cost the same over less area.
- Days on market
- How long a comp took to sell. Useful context the per-foot figure cannot carry.
Good to know
What an appraiser does that this does not
Residential appraisal is a sales comparison process, and price per square foot is one input to it rather than the method. An appraiser selects three to six recent sales that are genuinely comparable, then adjusts each one line by line: so much for a finished basement, so much for a third bathroom, so much for a two-car garage against a one-car, so much for condition, so much for lot size, so much for a market that moved between the comp's contract date and today. The adjusted comps then bracket the subject's value. Price per square foot is a sanity check applied to that result, not a substitute for it. Where this page helps is in spotting something wildly out of line before you spend time on it — a 20% premium against the comp average is a question worth asking; a 0.2% premium is not.
Why the weighting is dollar-weighted rather than averaged
There are two ways to blend comps and they give different answers. Averaging the three individual per-foot figures weights each comp equally regardless of size. Dividing total comp price by total comp square footage weights each by its size, which is what appraisers do and what this page does. Here the two are close — $223.24 against $223.13 — because the comps are similar in size. Add a small cottage at $260 a foot and the simple mean jumps while the weighted figure barely moves, which is the whole reason for the choice. Small properties reliably show higher per-foot figures because kitchens, bathrooms, furnaces and roofs cost roughly the same over less area, so an unweighted average of mixed sizes systematically overstates the market for the larger homes in the set.
Square footage is measured, and the measurements disagree
The standard is finished, above-grade living area, measured to the exterior walls — the ANSI standard that most appraisers and, since 2022, Fannie Mae require. Basements are excluded or reported separately even when fully finished, because below-grade space does not carry the same value per foot. Garages, unheated porches, attics and any space you cannot walk into standing up are excluded. Listings do not always follow this. Square footage in an MLS entry may include a finished basement, a converted garage, an addition built without a permit, or simply the number the previous listing used. Before concluding a price is high or low, check what the area figure covers on both the subject and every comp — a comparison built on two different definitions is arithmetic on nothing.
Choosing comps, and what disqualifies one
A comparable sale should be closed rather than listed, recent — three to six months in a stable market and less in a moving one — in the same neighbourhood and school attendance zone, of similar size within roughly 20%, similar age, similar style and similar condition. Things that quietly disqualify a comp: a sale between family members, a foreclosure or short sale, an estate sale, a seller concession that inflated the recorded price, a property with a materially different lot, and anything across a boundary that buyers price differently — a school zone, a flood zone, a municipal line with a different tax rate. Active listings are not comps; they are asking prices, and in a soft market the gap between asking and closing is exactly the information you are trying to find.
Where the metric works, and where it misleads
It works best in tract subdivisions of similar homes built in the same era, which is where the comparison it assumes is closest to true. It works poorly in older neighbourhoods with varied housing stock, on unusual lots, in markets where a view or waterfront dominates, and on any property with a feature the metric cannot see. It also has a systematic bias worth naming: within any market, small homes show a higher price per foot than large ones, so comparing a 1,200-square-foot bungalow with a 3,000-square-foot colonial produces a difference that reflects size rather than value. If you use one number from this page, use the implied value rather than the per-foot figure — it applies the comp market to your specific area, which is at least the right shape of question.
Frequently asked questions
Is price per square foot a good way to value a home?
It is a sanity check, not a valuation. It cannot see a finished basement, a new roof, a corner lot, a renovated kitchen or a school boundary — all of which move price more than floor area does. Use it to spot something wildly out of line, then look at the actual homes.
Why is the comp average dollar-weighted?
Because that is what an appraiser does. Adding the three prices and dividing by the three square footages weights each comp by its size, which stops a small comp with an unusual per-foot figure from dominating. Averaging the three per-foot numbers instead would give each equal weight regardless of size.
What makes a good comparable?
Same neighbourhood, sold in the last three to six months, similar size, similar age, similar condition, and similar style. A comp half a mile away across a school boundary is not a comp. Appraisers generally use three to six and adjust each one for differences.
Why do smaller homes cost more per square foot?
Because the expensive parts do not scale. A kitchen, a bathroom, a furnace, a roof and a foundation cost roughly the same on a 1,400-square-foot home as on a 2,400-square-foot one, so the fixed cost is spread over less area. Comparing a small home with a large one on this metric is misleading in both directions.
What square footage should I use?
Finished, above-grade living area, which is what the MLS normally reports and what appraisers measure. Basements are usually excluded or counted separately even when finished, and garages, porches and attics are excluded. Use the same standard for every comp or the comparison collapses.
How much variation is normal?
Five to ten percent between similar homes in the same neighbourhood is ordinary. Beyond fifteen percent something specific is driving it — condition, a lot, an update, or a motivated seller. That is the point at which the number is telling you to look closer.
Does this work in every market?
It works best in tract subdivisions where homes are genuinely similar. It works poorly in older neighbourhoods with varied housing stock, on unusual lots, or anywhere a view or waterfront dominates value.
Can I use it to negotiate?
Modestly, and better with the comps themselves than with the average. "Three similar homes on this street closed at $223 a foot and you are asking $265" is an argument. "Your price per square foot is high" is not.
Why does the listing's figure differ from mine?
Usually a square footage disagreement. Listings sometimes include finished basements, converted garages or additions that were never permitted. Check what area the number covers before concluding the price is wrong.
Is this the same as construction cost per square foot?
No, and confusing them is common. Construction cost is what it costs to build — commonly $150 to $400 a foot depending on region and finish. Price per square foot is what a finished home sells for, and it includes the land.
Can I replace an appraisal with this?
No. An appraiser measures the property, selects comps, and adjusts each one line by line for differences in condition, size, lot, garage and updates. This does the arithmetic that sits underneath that work, without any of the judgement.
How many comps do I need?
One is better than none and three is meaningfully better than one. The page uses whatever you enter and ignores blanks, so start with the best comp you have and add more as you find them.