How DealGapIQ Calculates the Deal Gap

By Brad Geisen · Last updated May 10, 2026

Most real estate analysis tools are black boxes. You enter an address and get a number. We don't do that. This page documents how the IQ Estimate, Target Buy, Income Value, and Deal Gap are produced — what data feeds them, what we model, and what we deliberately do not.

The three numbers DealGapIQ produces

Target Buy

The price at which a property meets the return thresholds for a given investment strategy. If you offer at or below the Target Buy, the strategy pencils on the assumptions in front of you. Computed independently for each of the six strategies, since each strategy values the same property differently.

Income Value

The maximum price at which the property still produces positive cash flow under a given strategy. It's the ceiling beyond which the deal stops covering itself, even if appreciation is your thesis.

Deal Gap

The percentage distance between the asking price and the Target Buy. A positive Deal Gap means the asking price is above what the strategy supports. A negative Deal Gap means the property is already priced below your Target Buy — rare, and worth a closer look.

The data layer

No single data source is sufficient for residential investment analysis. Each source has coverage gaps, refresh-cadence limitations, and a methodology built for a different audience. DealGapIQ blends multiple sources so a weakness in any one doesn't poison the analysis.

Zillow— listing data and Zestimate (built for homeowners, not investors; we use it as one input, not the answer).
RentCast— rental comparables and short-term rental performance signals.
Redfin— listing data and recent comparable sales.
Realtor.com— listing data and market metrics.
Mashvisor— investment-grade rental and STR analytics.
IQ Estimate— our own model, blended from the above plus public records and tax assessor data.

The IQ Estimate

The IQ Estimate is the blended valuation we use as the starting point for every strategy calculation. It is not a replacement for an appraisal; it's a fast, multi-source consensus that gives you a defensible number to work from. When the underlying sources agree, the IQ Estimate is tight. When they disagree, the analysis flags the divergence so you know the data is contested before you act on it.

Six strategies, six different valuations

The same property is worth different amounts under different strategies. A house that doesn't pencil as a long-term rental can be a strong fix-and-flip; a house that fails as a flip can be a cash-flow winner with the right financing structure. DealGapIQ runs every property against all six strategies and ranks them by fit.

Long-Term Rental — cash flow on annual leases.
Short-Term Rental — ADR, occupancy, RevPAR.
BRRRR — ARV, refi cash-out, capital recycling.
Fix & Flip — MAO, rehab budget, holding costs.
House Hack — FHA/VA financing, rent offsets, owner-occupant rules.
Wholesale — assignment-fee math from the buyer's MAO.

Editable assumptions

Every assumption that drives the math is editable in DealMaker: down payment, interest rate, loan term, property taxes, insurance, vacancy, management fees, repairs, capex reserve, rehab budget, exit costs. Defaults are conservative. Sensitivity analysis lets you see how Discovery shifts when an assumption changes — so you can stress-test the deal before you stress-test it with real money.

Creative finance

Subject-To, seller carrybacks, 0% seconds, the Morby Method, and loan assumptions are first-class structures in DealMaker. Plug in the seller's loan balance and rate and the math runs against the actual capital stack — not just “20% down, today's rate.” Worked examples and risks are in the glossary.

What we deliberately do not model

Appreciation forecasts. We do not project a specific price growth rate. Long-horizon appreciation is too sensitive to macro conditions, local supply, and policy to be useful in a per-deal Discovery. You can model your own appreciation assumption in DealMaker for the 10-year projection.
Tax strategy.Depreciation, 1031 exchanges, cost segregation, opportunity zone treatment — all out of scope. Your CPA owns this; we don't want to give you a number that depends on personal tax facts we can't see.
Macro market timing. We score the deal in front of you, not the cycle around it.
Insurance specifics.We use category-typical insurance estimates. Specialty coverage (flood, wind, earthquake, vacant-property policies) requires a quote — the platform's estimate is a placeholder, not a binder.

Editorial principles

Numbers over narratives. Listing copy is written to sell. Discovery is written to inform.
Transparent assumptions.Every input is visible and editable. We don't hide methodology behind a paywall or a marketing wrapper.
Conservative defaults.When in doubt, the default assumption is the one that makes the deal look worse. You should be the one talking yourself into a deal — not us.

Important disclosure

DealGapIQ provides analytical estimates and decision-support tools. Outputs are educational and do not constitute investment, legal, tax, or financial advice. Estimates are not appraisals. See the full disclosures for data-source limitations, jurisdiction notes, and affiliate relationships.

Changelog

2026-05-10— Initial public methodology document.

Run a free Discovery on any property →

The three numbers DealGapIQ produces

Target Buy

Income Value

The maximum price at which the property still produces positive cash flow under a given strategy. It's the ceiling beyond which the deal stops covering itself, even if appreciation is your thesis.

Deal Gap

The data layer

Zillow— listing data and Zestimate (built for homeowners, not investors; we use it as one input, not the answer).

RentCast— rental comparables and short-term rental performance signals.

Redfin— listing data and recent comparable sales.

Realtor.com— listing data and market metrics.

Mashvisor— investment-grade rental and STR analytics.

IQ Estimate— our own model, blended from the above plus public records and tax assessor data.

The IQ Estimate

Six strategies, six different valuations

Long-Term Rental — cash flow on annual leases.

Short-Term Rental — ADR, occupancy, RevPAR.

BRRRR — ARV, refi cash-out, capital recycling.

Fix & Flip — MAO, rehab budget, holding costs.

House Hack — FHA/VA financing, rent offsets, owner-occupant rules.

Wholesale — assignment-fee math from the buyer's MAO.

Editable assumptions

Creative finance

What we deliberately do not model

Appreciation forecasts. We do not project a specific price growth rate. Long-horizon appreciation is too sensitive to macro conditions, local supply, and policy to be useful in a per-deal Discovery. You can model your own appreciation assumption in DealMaker for the 10-year projection.

Tax strategy.Depreciation, 1031 exchanges, cost segregation, opportunity zone treatment — all out of scope. Your CPA owns this; we don't want to give you a number that depends on personal tax facts we can't see.

Macro market timing. We score the deal in front of you, not the cycle around it.

Insurance specifics.We use category-typical insurance estimates. Specialty coverage (flood, wind, earthquake, vacant-property policies) requires a quote — the platform's estimate is a placeholder, not a binder.

Editorial principles

Numbers over narratives. Listing copy is written to sell. Discovery is written to inform.

Transparent assumptions.Every input is visible and editable. We don't hide methodology behind a paywall or a marketing wrapper.

Conservative defaults.When in doubt, the default assumption is the one that makes the deal look worse. You should be the one talking yourself into a deal — not us.