For Real Estate Investors
Calculators built by a landlord with 200+ units across New England, not by a finance content farm. Defaults pulled from real operating data.
Quick filter sequence for a new listing: GRM (under 12?) → 1% rule (above 0.7%?) → cap rate (above 6%?) → full Rental Property analysis. If a deal fails any of the first three, stop. If it passes all three, run the full analysis. This saves hours of work on deals that were never going to pencil.
Rental Property Calculator
Cash flow, cap rate, cash-on-cash, 1% rule, 50% rule.
The first calculator I'd run on any new deal.
Cash Flow Calculator
Per-door cash flow with all reserves.
Cash flow per door is the metric that scales — not gross dollars.
Cap Rate Calculator
NOI ÷ price + benchmark price table.
What brokers quote. Useful for comparing across deals; not the deciding metric for your investment.
Multifamily Calculator
5+ unit commercial w/ DSCR, per-unit metrics.
When you cross 5 units, you're in commercial — different rules apply.
DSCR Calculator
Pass/fail commercial loan threshold + max loan at target DSCR.
The metric commercial lenders care about more than your credit score.
BRRRR Calculator
Buy, Rehab, Rent, Refinance, Repeat — full cash-out math.
Includes the 75% rule check + infinite return detection.
70% Rule (MAO) Calculator
Maximum allowable offer for flips.
Quick filter before you waste time on a deal that doesn't pencil.
Single-Family Investment
5-year projection w/ appreciation + rent growth + IRR.
The four ways single-family rentals make money — all in one calculator.
Pro Forma Calculator
5-year multifamily pro forma w/ stabilization year + exit cap.
Stress-test broker pro formas with your actual stabilization assumptions.
Vacancy Rate Calculator
Cost of one extended turnover, annualized.
Vacancy is the silent portfolio killer — see it in dollars per day.
Operating Expense Ratio
OER w/ industry benchmarks.
How efficient your property actually is, normalized for size.
GRM Calculator
Gross rent multiplier — quick deal compare.
Back-of-envelope filter when you have 20 listings and 30 minutes.
1031 Exchange Calculator
Defer capital gains via like-kind exchange.
When it's time to roll a deal into the next one — see the boot, see the tax.
Depreciation Calculator
27.5-year residential / 39-year commercial.
The unsung hero of real estate returns. Always claim it.
Cash-Out Refinance Calculator
Cash available + break-even on closing costs.
When you've built equity and want to deploy it into the next deal.
Section 8 Rent Calculator
HAP + tenant portion + total rent received.
Reliable government-paid income — worth understanding before you accept your first voucher.
Rent-to-Income Calculator
Tenant screening: 30%/33%/40% threshold check.
Don't reject someone solely on this — but use it as a filter.
Seller Financing Calculator
Owner-financed loans with balloon.
The most underused tool in real estate. Worth knowing how the math works.
What I'd tell my younger self
I scaled from 0 to 100 units in 12 years while holding a full-time engineering job. Then 100 to 200+ in the next 4 years after I lost the day job. The second phase was technically faster, but operationally it nearly broke me. The calculators here will help you make better decisions on individual deals. They won't tell you when to stop. That's the harder skill, and the one I wish I'd learned sooner.