Follow the calculation.

Shared engines, visible inputs

Rental tools use a single model for income, vacancy, operating expenses, reserves, financing and cash flow. NOI excludes debt service, income tax, depreciation and capital reserves. The reserve is deducted when calculating spendable cash flow. Percentage operating expenses use collected income.

Seller tools separate debt payoff from sale costs and tax basis. Proceeds are cash after payoff; gain is sale proceeds less selling expenses and adjusted basis. These are different numbers. Mortgage payoff does not reduce taxable gain.

Dates, interest and rounding

Calendar dates are processed in UTC to avoid daylight-saving shifts. Rent proration includes the occupancy date. Payment calculations use a fixed rate and monthly compounding. Inputs and internal calculations retain precision; the screen rounds currency to whole dollars except rent-split tables, which reconcile to cents. CSV schedules retain the underlying numbers.

Annual IRR uses year-end cash flows and a final-year sale. The bisection method reports a bracketed root; unusual cash-flow patterns can have multiple roots or no meaningful IRR. Annualized flip ROI assumes repeatable reinvestment and is not a forecast.

Tax model coverage

The gain tool assumes long-term property gain and straight-line real-property depreciation. Rates, eligibility and state effective tax are manual assumptions. It does not determine brackets, filing obligations, nonqualified-use allocation or §1245 recapture. Depreciation uses the GDS straight-line mid-month model; cost segregation uses illustrative user allocations and simplified nonbonus deductions.

A 1031 calculation assumes eligible investment/business real property and a fully funded exchange. It displays cash/debt boot and the earlier of 180 days or the entered tax-return deadline. A qualified intermediary and tax professional must establish the actual structure.

State data and map measurement

State records distinguish checked rules from manual quote modes. County identifiers and names come from the 2025 Census Gazetteer. Current local millage is awaiting verification and is never filled with an invented county average. Michigan additionally offers the dated 2025 Treasury district reference for that tax year. Use certified parcel values, rates and current exemptions.

Map acreage uses a spherical polygon model with WGS84 geographic coordinates and a mean Earth radius. It estimates horizontal area and great-circle perimeter. Simple nonintersecting polygons and dimensions are supported; the tool is not a legal boundary survey.

Verification and updates

Formula checks cover representative examples, thresholds, zero rates, cent reconciliation and default scenarios. Rule verification and independent professional review are distinct. State data is scheduled for quarterly editorial review; annual rates and thresholds also need checks at their effective dates. Search-performance rules can keep incomplete or nonperforming state pages out of the index while leaving them reachable from the hub.