Free lot math · No sign-up
Lot Premium Comparison Estimator (new-construction lots)
Independent consumer calculator. Not affiliated with any government agency, lender, builder, MLS, appraisal district, tax authority, or other service provider unless expressly identified on the relevant placement.
A lot premium is the extra amount a builder quotes above the base lot price for a specific homesite. This calculator organizes that premium next to comparable lot prices you supply from the same subdivision — each with a source and date — and next to your own dollar weights and scores for the lot's features. The output is comparison evidence and buyer-entered scenario arithmetic: a premium percentage, a comparable range and median when the evidence qualifies, and a modeled net difference under your assumptions. When fewer than two comparables are both same-subdivision and source-dated, the calculator reports not enough evidence instead of a partial figure.
This is a user-entered lot-comparison worksheet, not an appraisal, valuation, market opinion, fair-market-value estimate, or recommendation. It does not determine whether a lot is worth its premium. Builder disclosures and a qualified appraiser control.
Worked example
Worked example: a $18,000.00 premium on a $120,000.00 base lot, with three source-dated comparables
| Comparable lot | Listed price | Difference vs base lot price |
|---|---|---|
| Lot 14 | $128,000.00 | $8,000.00 |
| Lot 22 | $135,000.00 | $15,000.00 |
| Lot 31 | $126,500.00 | $6,500.00 |
| Median | $128,000.00 | $8,000.00 |
Premium as % of base lot price
15%
Modeled net difference (buyer scenario)
$4,900.00
The quoted premium is 15% of the base lot price. The three qualifying comparables span $126,500.00 to $135,000.00, with a median of $128,000.00 — $8,000.00 above the base lot price. The buyer's own weights and scores produce a modeled feature value of $13,100.00, leaving a modeled net difference of $4,900.00 versus the quoted premium. Every figure is comparison evidence and buyer-entered scenario output under these inputs.
This is a user-entered lot-comparison worksheet, not an appraisal, valuation, market opinion, fair-market-value estimate, or recommendation. It does not determine whether a lot is worth its premium. Builder disclosures and a qualified appraiser control.
Interactive
Run your own numbers
This is a user-entered lot-comparison worksheet, not an appraisal, valuation, market opinion, fair-market-value estimate, or recommendation. It does not determine whether a lot is worth its premium. Builder disclosures and a qualified appraiser control.
Comparable lots (same subdivision, source-dated)
Buyer-entered features (dollar weight × score 0–10)
Premium as % of base lot price
15%
Quoted premium
$18,000.00
Comparable-lot evidence (3 lots)
Prices span $126,500.00 to $135,000.00 with a median of $128,000.00. Versus your base lot price, the differences run $6,500.00 / $8,000.00 (median) / $15,000.00.
Buyer-entered scenario
Your modeled feature value is $13,100.00, leaving a modeled net difference of $4,900.00 versus the quoted premium. This is comparison evidence and buyer-entered scenario output — arithmetic on the weights and scores you chose.
| Weight scale | Modeled feature value | Modeled net difference |
|---|---|---|
| ×0.5 | $6,550.00 | $11,450.00 |
| ×0.75 | $9,825.00 | $8,175.00 |
| ×1 | $13,100.00 | $4,900.00 |
| ×1.25 | $16,375.00 | $1,625.00 |
| ×1.5 | $19,650.00 | -$1,650.00 |
This is a user-entered lot-comparison worksheet, not an appraisal, valuation, market opinion, fair-market-value estimate, or recommendation. It does not determine whether a lot is worth its premium. Builder disclosures and a qualified appraiser control.
The math
How the math works
The premium percentage is premium ÷ base lot price × 100. Each comparable difference is that lot's price minus the base lot price, and the range and median are reported only when at least two comparables are both same-subdivision and source-dated — otherwise the calculator shows not enough evidence. The modeled feature value is the sum of your dollar weight × score for each feature, and the modeled net difference is the quoted premium minus that total. The sensitivity table rescales your combined weights by 0.5×, 0.75×, 1×, 1.25×, and 1.5× and recomputes the net difference at each step. All money values round half-up to cents.
Fine print
Assumptions and limitations
- Every lot price, comparable price, dollar weight, and score is a user-entered input. Nothing is pulled from an MLS, assessor, builder system, or map, and nothing is verified.
- The comparable statistics summarize only the entries you marked same-subdivision and source-dated. Fewer than two qualifying entries produce the not enough evidence state, never a partial statistic.
- The modeled feature value and modeled net difference are comparison evidence and buyer-entered scenario arithmetic — they quantify your own assumptions and change whenever your weights or scores change.
- This tool draws no conclusion about zoning, title, environmental condition, resale, or site condition, and it never tells you to take or skip a lot.
- This is a user-entered lot-comparison worksheet, not an appraisal, valuation, market opinion, fair-market-value estimate, or recommendation. It does not determine whether a lot is worth its premium. Builder disclosures and a qualified appraiser control.
Important: This independent consumer calculator provides estimates for education and comparison only. It is not a lender, mortgage broker, builder, real estate broker, appraiser, tax professional, attorney, financial adviser, or government agency, and it is not an offer, quote, approval, commitment, Loan Estimate, Closing Disclosure, appraisal, inspection, or other legal or financial document. Results are not a guarantee of savings, payment, qualification, price, availability, or outcome. Verify all figures, terms, eligibility, fees, taxes, HOA/MUD/PID charges, incentives, construction terms, and provider disclosures with the relevant provider and a qualified professional before relying on them. We do not provide legal, tax, mortgage, lending, or investment advice.
Answers
Frequently asked questions
What is a lot premium?
A lot premium is the extra amount a builder quotes above the community's base lot price for a specific homesite — usually for attributes such as a view, orientation, privacy, yard size, or position in the subdivision. It is a builder pricing decision stated on the builder's own price sheet, and the written purchase documents control what it covers.
Where do the comparable lot prices come from?
You supply them, from the builder's current price sheet or other written material for the same subdivision, together with the source and date. The calculator only summarizes what you enter; it does not pull, verify, or update any price. Statistics are shown only when at least two entries are marked both same-subdivision and source-dated.
Why does the tool sometimes show a not enough evidence state?
When fewer than two comparable lots are marked both same-subdivision and source-dated, the calculator withholds the range and median entirely. A statistic built from one entry, an undated flyer, or a different community would be misleading, so the tool reports not enough evidence instead of a partial figure.
What is the modeled feature value?
It is your own arithmetic: for each feature you choose a dollar weight per point and a 0-10 score, and the calculator multiplies and sums them. The modeled net difference is the quoted premium minus that total. Both numbers are comparison evidence and buyer-entered scenario output — they describe your assumptions, not the market.
What does the sensitivity table show?
It rescales your combined feature weights by 0.5x through 1.5x and recomputes the modeled net difference at each step. That shows how strongly the scenario depends on the weights you picked: if the sign of the net difference flips within that band, the scenario is sensitive to your own assumptions and deserves more evidence before you rely on it.
References
Sources
- Fannie Mae Selling Guide B4-1.3-06 — comparable-sales requirements
- The Appraisal Foundation — USPAP professional standards
These sources describe comparable-sales principles and professional standards. They do not supply a lot-premium formula, and this calculator does not perform the analyses they govern.
Updated 2026-08-17.
Worksheet
Take it to the sales office
The printable Lot Decision Evidence Pack packages your comparables and scenario into a comparison grid for the builder meeting — where to record each price's source and date, which questions pin down what the premium covers, and what to ask a qualified professional before you sign. The pack carries the same lot-comparison sentence shown above.
Disclosure: We may receive a flat fee or commission if you use some links or offers on this page. This does not change the calculator result. You are not required to use any listed provider.
Sponsor placement available. Affiliate and sponsor disclosure.