Draw factor — construction loans fund in draws, not lump sum, so interest is only charged on the portion actually drawn. ~30% of a fully-annualized interest figure approximates real carry cost over a typical build cycle.
Site Capacity — What Will This Lot Support?
This is a feasibility screen, not an entitlement — verify actual density, coverage, height, and parking requirements with the city's zoning code before you tie up land. It checks your building's unit size/common-area assumptions above against three independent caps: allowed density, lot coverage + height envelope, and parking area.
Bank Financing — the "two spreadsheet" method
You budget this project twice. Execution budget is what you actually pay subs/suppliers. Retail (bank) budget marks every line item up, and it's what the bank underwrites against. The spread between the two is the equity the bank sees on day one.
If you plan to sell instead of hold
Est. equity created (12 mo. hold)
$0
Stabilized value minus all-in cost
Site Capacity Verdict
—
Max units — density cap0
Max units — coverage + height envelope0
Max units — parking0
Max units this lot supports0
Units you're underwriting above0
Whichever of the three caps is lowest is your real ceiling — that's usually parking or lot coverage, not the density number on the zoning map.
Income
Gross potential rent / yr$0
Less vacancy$0
Effective gross income$0
Operating expenses$0
Net operating income (NOI)$0
Value
NOI ÷ cap rate—
Stabilized value$0
Cost to build
Building sf (incl. common area)0 sf
Hard + soft cost$0
Land$0
Construction interest carry$0
Total project cost$0
$ / door value
$0
$ / door cost
$0
Yield on cost
0%
Bank Financing
Execution budget (your real cost)$0
Retail (bank) budget$0
Bank loan (LTC × retail budget)$0
Equity bank sees at closing$0
Cash needed out of pocket$0
If Sold (net of closing costs)
Stabilized value$0
Less selling / closing costs$0
Less execution cost$0
Net profit if sold$0
Subject Property
$
$
$
$
Comps → ARV
Enter recently sold comps to set ARV (after-repair value), and active/on-market listings as a sanity check on where the market's heading. Ask me to pull comps for a specific address and I'll search and fill these in for you.
Sold comps
Sold price
SF
$/sf
Avg $/sf (sold)$0
Active / on-market
List price
SF
$/sf
Avg $/sf (active)$0
$
Hard Money Financing
Est. net profit at ARV
$0
Resale price minus all-in cost and selling costs
—
70% Rule Check
ARV$0
ARV × 70%$0
Less rehab budget$0
Max allowable offer$0
Your purchase price$0
Room under/over MAO$0
Total Project Cost
Purchase price$0
Rehab budget$0
EMD / other$0
Holding costs (monthly × months)$0
HML points + interest$0
Total project cost$0
Financing
HML loan amount (LTV × ARV)$0
HML points cost$0
HML interest cost (term)$0
Cash needed to close$0
Exit
Resale price (ARV)$0
Less commission + closing$0
Net proceeds$0
Profit as % of cost
0%
$/sf all-in
$0
$/sf ARV
$0
Subject Lot / Address
$
Splitting one parcel into multiple buildable lots — e.g. a 2.5-acre plot as 2 houses. Land price above is the whole parcel's purchase price and gets split across every lot automatically; build size/cost/resale (everything else on this tab) is assumed to be the same house repeated on each lot. Leave at 1 for a single house on a single lot — every number below is identical to how this tab always worked.
Comps → Resale Price
Underwrite like the bank: they'll pull comps and price your resale at the average $/sf, not your best-case number. Enter recent sold comps of homes similar in size/finish in the immediate area. Ask me to pull comps for a specific address and I'll fill these in.
Sold price
SF
$/sf
Avg $/sf (sold comps)$0
Rule of thumb from the transcripts: below ~$285/sf in resale comps, there's little to no profitability in a spec build. $300+/sf is where the margin starts working.
Buildable Envelope — What Fits On This Lot?
Assumes a roughly square lot and fills in width/depth below — override either one after if your lot is a different shape.
Feasibility screen only — pull actual setback, coverage, and height limits from the city's zoning code before relying on this for a purchase decision.
Build Cost & Financing
National average self-performed is ~$139–141/sf (NAHB). Hiring a general contractor on a cost-plus or flat-fee model (recommended over a custom builder, who'll price at $300+/sf and eat your margin) typically runs $155–167/sf all-in — architecture, engineering, permits, impact fees, foundation, and framing included.
Bank Underwriting (After-Build Value)
Banks typically lend 75–80% loan-to-value against the after-build value (ABV) on construction — the remaining 20–25% is your required equity/profit margin. Separately, land should run no more than 15–20% of resale price on builds under $1.5M (up to 25% above that) — pay more and you're eating your own margin before you've broken ground.
Costs auto-derive from each lot size below — no need to enter road footage, tap fees, or engineering per scenario. Formula (regional OK/AR/MO/TX default): net sellable factor 60% under 0.3ac, 64% under 0.6ac, 70% under 1.1ac, 78% for 1.1–2ac, 85% at 2ac+ (bigger lots waste less land to roads/easements). Road frontage 75/90/110/65/20 LF per lot across those same bands, at $165/LF. Water+sewer tap $9,000/lot under 1ac, $3,000/lot 1–2ac, $1,500/lot at 2ac+ (well/septic range). Electric $4,000/lot under 1ac, $1,500/lot at 1ac+. Engineering/survey/plat: $35,000 base + $1,500 per net lot, split across lots. City/permit fees flat $600/lot. This is a planning-stage estimate, not a quote — a civil engineer's preliminary plat gives you the real number once you have one.
These apply to every property below unless you're modeling very different deal terms — for acquisition of existing (not ground-up) property, so vacancy and opex run higher than new construction: 35–50% opex ratio is normal for stabilized or older rentals, vs. the 20% used in the New Build mode.
Current rent roll income stays as your baseline. The value-add bump = (market rent − current rent) × proforma unit count (current + added units) × 12 — added on top of baseline to get proforma potential rental income. Stabilized value is priced off current NOI at your valuation cap rate, not the proforma NOI, so the value-add upside isn't double-counted into what you're allowed to pay today.
Expenses (per unit / year unless noted)
$
$
$
$
Valuation, Financing & Fees
Your max loan is the lesser of an LTV-based loan (Max Allowable Offer × LTV%) and a DSCR-based loan (the biggest loan current-year NOI can service at your minimum DSCR, amortized over your loan term) — same "min of both" test a lender actually runs.
Max Allowable Offer is now the lowest of three independent tests, same as a real underwriter would run: Cost Basis (target basis % of stabilized value, minus renovations), DSCR (the highest price where a DSCR-sized loan still fits your Max LTV — above this price DSCR becomes the binding loan constraint, not LTV), and Target ROI (the highest price where your cash-on-cash return still hits the target above, solved backward off current-year NOI). Whichever is lowest sets your real ceiling — shown as "binding" below the headline number.
Hold Period & Simplified Proforma
Simplified vs. the source napkin's year-by-year rate grid: one flat rent-growth % and one flat expense-growth % are applied every year of the hold, starting from Year 1 proforma income/expenses (value-add fully reflected from Year 1). Vacancy % stays constant at the rate set above for every year.
Max Allowable Offer
$0
Target cost basis minus renovation + contingency budget
—
Ideal Purchase Price — Cap Rate Method
$0
Current NOI ÷ Valuation Cap Rate (8.0%)
—
This is the plain cap-rate valuation — Current NOI ÷ Valuation Cap Rate, nothing else. Max Allowable Offer above is a stricter, more realistic ceiling: it's the lowest of three tests (cost basis %, DSCR loan limit, target ROI), so it's often below this number. Use MAO as your real max offer; use this one as a quick gut-check against the raw cap rate math a broker or a simple BOV is usually quoting.
Rent Roll & Value-Add
Current gross potential rent (GPR)$0
Delta increase /unit$0
Value-add income /yr$0
Proforma potential rental income$0
Value add (capitalized)$0
Rent $/sf/mo$0.00
First-Year Operating Statement
CurrentProforma
Potential gross income$0$0
Vacancy & credit loss$0$0
Effective gross income$0$0
Total expenses$0$0
Net operating income (NOI)$0$0
Operating margin0%0%
Value & Max Allowable Offer
Stabilized value at cap rate (= ideal purchase price, above)$0
Self-storage demand is driven by rooftops within a 1–5 mile ring, not the metro number — the population lookup opens a free radius tool where you can drop a pin on the exact site. Give me the address directly and I can also pull current population and growth figures for you.
Building
Net rentable efficiency accounts for hallways, drive aisles inside the building, and walls — the footprint isn't 100% rentable square footage.
$
Non climate-controlled single-story typically runs $45–65/sf all-in. Climate-controlled and/or multi-story with elevators runs $65–100+/sf — adjust the slider for your build type.
Revenue & Operations
$
Value & Financing
Self-storage typically finances closer to actual cost (LTC against appraised value) rather than the retail-markup mechanic used for ground-up multifamily — lenders in this asset class scrutinize lease-up projections closely since stabilization can take 3–5 years.
In a triple-net (NNN) lease the tenant pays base rent plus their share of taxes, insurance, and maintenance — the "pass-throughs" below are reimbursed and NOT counted as landlord NOI. Your landlord income is just the base rent, reduced by vacancy/credit, management, and long-term capex reserves.
Revenue (NNN structure)
$
$
Operating Costs (landlord-paid)
$
Financing
%
Year-1 cash-on-cash (levered)
$0
Year-1 cash flow ÷ total equity in the deal
Revenue & NOI
Gross base rent / yr (sqft × $/sf)$0
NNN pass-throughs (reimbursed)$0
Less vacancy / credit loss$0
Effective gross income$0
Management fee$0
Reserves / capex$0
Net operating income (NOI)$0
Valuation & Capital
Unlevered cap rate (NOI ÷ price)—
Price per sqft$0
Loan amount (LTV × price)$0
Equity (price + acq costs − loan)$0
Annual debt service$0
Year-1 cash flow (NOI − DS)$0
Debt service coverage (DSCR)—
Leverage spread (cap − interest rate)—
⚠️ Negative leverage — borrowing costs more than the property yields; additional leverage reduces cash-on-cash.
RV parks and campgrounds typically finance against stabilized value / DSCR rather than raw cost, and lenders scrutinize lease-up projections closely since reaching stabilized occupancy can take 1–3 full seasons. The interest-carry here uses your avg draw factor on the combined build + land cost during construction.
Est. equity created (stabilized)
$0
Stabilized value minus all-in cost
Site Capacity
Developable area0 sf
Total sites (density × developable ac)0
Revenue
Gross potential rent / yr$0
Less vacancy / economic loss$0
Plus ancillary income$0
Effective gross income$0
Operating expenses$0
Net operating income (NOI)$0
Value
NOI ÷ cap rate—
Stabilized value$0
Cost to Build
Build cost (sites × cost/site)$0
Site improvements + amenities$0
Land$0
Construction interest carry$0
Total project cost$0
Financing
Bank loan (LTC × total cost)$0
Cash needed out of pocket$0
$/site value
$0
$/site cost
$0
Yield on cost
0%
Loan Terms
$
Interest-only period is common on construction-to-perm and bridge loans — no principal is paid down during this window, so the payment is lower but the balance doesn't shrink.
$
Monthly payment (P&I, post interest-only)
$0
—
Summary
Interest-only payment (if applicable)$0
Total interest paid to balloon/payoff$0
Total of payments to balloon/payoff$0
Remaining balance at balloon$0
Payoff date (months)
0
Interest saved vs. no extra pmt
$0
Amortization Schedule (first 12 + every 12th month)
Mo.
Payment
Principal
Interest
Balance
Subject Property
A "slow flip" isn't a renovation flip — it's note arbitrage. You buy the property on one note (from a private lender or the seller), then immediately resell it to a retail buyer on a second, separate seller-financed note at better terms. You pocket the down-payment spread, the monthly payment spread while both notes run, then the buyer's entire payment as pure profit once your own note is paid off.
Buy Side — Your Note
$
$
$
Sell Side — Buyer's Note
$
$
$
$
Target payment → solve rate (matches the source spreadsheet): you pick a clean round number the buyer will pay each month, and the implied note rate is solved backward with an iterative RATE()-style search — no closed-form solution exists for rate. I know the rate → solve payment: you set the buyer's rate directly and the standard payment formula computes their monthly P&I.
Tax + Insurance Escrow & Goal
$
$
Total profit over full term
$0
Phase 1 + phase 2 cash flow, plus down-payment spread
—
Down Payment Spread
Your down payment (out)$0
Buyer's down payment (in)$0
Down payment spread$0
The Two Notes
Your noteBuyer's note
Financed amount$0$0
Rate0%0%
Term (years)00
Monthly P&I$0$0
Buyer's total incl. escrow$0
Monthly tax + insurance escrow held$0
Cash Flow — Phase 1 (Years 1–5, both notes active)
Your Note — Amortization (first 12 + every 12th month)
Mo.
Payment
Principal
Interest
Balance
Buyer's Note — Amortization (first 12 + every 12th month)
Mo.
Payment
Principal
Interest
Balance
Save & Share This Underwrite
No saved underwrites yet — fill out either calculator above, name it, and click "Save This Underwrite." Saved deals live in this browser tab and are cleared on refresh, so export to Excel/CSV to keep them permanently.
Name
Type
Saved
Headline #
Excel downloads a workbook with separate tabs for Multifamily and Flip deals, every input and output as its own column. CSV downloads one flat file — in Google Sheets, use File → Import → Upload and pick "Insert new sheet," or just drag the CSV into a Google Drive folder and open it (Drive auto-converts it to a Sheet). Print / Save as PDF gives you a clean one-page summary of whichever calculator is currently open, sliders hidden — use your browser's "Save as PDF" option in the print dialog to email or text it.
Airtable
Uses the Airtable connection saved once on the Settings page — nothing to re-enter here. Create one Airtable table with these exact column names: Deal Name (text), Deal Type (single select or text), Date Saved (text), Headline (text), Details (long text). "Details" holds every field for that deal as readable JSON.
Sum of saved-underwrite headline numbers linked to non-closed contacts
Contacts
Synced to your account — a contact can be linked to any number of properties/deals (from here, Wholesale, or Deal Feed), each tracked at its own pipeline stage. Call/text/email auto-sync is a planned future phase.
No contacts yet — add a seller, agent, lender, or buyer to start tracking conversations against a deal.
Each linked deal tracks its own stage independently — closing one doesn't affect the others.
Not linked to any property or deal yet.
+ Quick-add a new property/deal
Follow-ups
Reminders live here in Backforty — nothing to set up. Overdue ones are flagged in red.
No follow-ups yet.
Conversation Log
Deal details
Load a Wholesale deal
Pulls address, purchase price, ARV, rehab budget, and size straight from a deal you already saved in the Wholesale calculator.
Load a Saved Deal
Pulls the loan amount, rate, and term from a deal you already saved on the Wholesale, Flip, SFH, or Portfolio tab — whichever of those has a clean single-loan figure to work with. Land, Multifamily, Storage, Napkin, and Slow Flip deals don't show up here (see the FAQ for why).
Load from Deal Feed
Pulls just the address from any property you've saved on Deal Feed or Wholesale into this tab's address field — everything else on this tab stays as-is.
🤖 Paste a Listing
Applies to whichever tab you're on. Paste a Zillow/Redfin/Crexi/LoopNet link and I'll try to read it directly — that often gets blocked by the site's bot protection, in which case paste the listing's visible text instead (select all on the page, copy, paste below) and I'll extract the same fields either way.
Review before applying — edit anything that looks off