Free Investor Tool
Work backwards from your target sale price to know exactly what to pay — whether you're flipping for profit or holding for rental income.
How it works
The 70% Rule is the investor's shorthand for making sure you never overpay. Here's the formula broken down step by step.
Step 1
$1,000,000
ARV
After Repair Value
Step 2
$700,000
70% Threshold
Your ceiling before rehab
Step 3 — Max Offer
$500,000
Maximum Purchase Price
After $200K rehab deducted
Interactive Calculator
Adjust the sliders to match your deal. The calculator instantly shows whether flipping or renting makes more sense.
Deal Inputs
Slide to match your property's numbers
70% Rule Output
ROI on invested
31.4%
Return on capital
Gross equity spread
50.0%
Built-in cushion
Strategy Breakdown
Both strategies use the same 70% Rule to protect your buy price. The difference is how and when you collect your profit.
Know the language
Every number in this calculator means something. Here's what each one is telling you about your deal.
ARV
After Repair Value
The estimated market value of the property after all renovations are complete. This is the number everything else is calculated from — it's what the property will sell or appraise for once it's fixed up.
"If comps in the area are selling at $1M after renovation, your ARV is $1M."
70%
The 70% Rule
An investor's rule of thumb: never pay more than 70% of the ARV minus rehab costs. That 30% buffer covers your holding costs, closing costs, commissions, and profit margin. It's a protection formula, not a profit formula.
"ARV $1M × 70% = $700K − $200K rehab = $500K max offer."
NOI
Net Operating Income
Your annual rental income minus operating expenses (vacancy, taxes, insurance, maintenance) — but before mortgage payments. NOI measures how much income the property itself generates, independent of how you financed it.
"$54K gross rent − $9K expenses = $45K NOI."
Cap Rate
Capitalization Rate
NOI divided by the property's value, expressed as a percentage. It tells you the return you'd earn if you paid all cash — a pure measure of the property's income potential, ignoring financing. Higher cap rate = better income relative to price.
"$45K NOI ÷ $1M value = 4.5% cap rate. Target 5–8% for most markets."
CoC
Cash-on-Cash Return
Your annual cash flow divided by the cash you actually put in (your down payment + closing costs). This is the most practical return metric for leveraged investors — it measures what your real dollars are earning each year.
"$7,700 annual cash flow ÷ $100K down = 7.7% cash-on-cash return."
1% Rule
Monthly Rent Threshold
A quick screening rule: monthly rent should equal at least 1% of the purchase price. It's a fast filter, not a guarantee. In high-value markets, hitting 1% is rare — but getting close tells you cash flow is in the right ballpark.
"$500K purchase × 1% = $5,000/mo rent needed to pass the rule."
P&I
Principal & Interest
The two components of your monthly mortgage payment. Principal reduces your loan balance (builds equity). Interest is the cost of borrowing. Together they're the largest expense for most rental investors.
"On a $400K loan at 7%, your P&I is roughly $2,660/mo."
ROI
Return on Investment
Net profit divided by total capital invested, as a percentage. For a flip, it measures your gain relative to everything you spent — purchase price, rehab, carrying costs, and closing costs. The higher the better.
"$220K profit ÷ $780K invested = 28.2% ROI on the flip."
Vacancy
Vacancy Rate
The percentage of time your unit sits empty between tenants. Even a well-managed rental will have occasional gaps. A 5% vacancy assumption means budgeting for roughly 18 days of lost rent per year. Smart investors always factor this in.
"5% vacancy on $4,500/mo rent = $225/mo buffer for empty periods."
Ready to Run a Real Deal?
I've been on both sides of these deals — as an operator and as an agent. If you've got a property in Northern NJ that pencils out, I want to hear about it.
Built for real estate investors who run their numbers before they run their mouth.