Real estate calculators

Property number crunching,
made simple.

Rule-based shortcuts, investment metrics, and deal analysis tools every property investor needs. From the 1% rule to BRRRR — enter your numbers and see if the deal stacks up.

Rental yieldCap rate & NOICash-on-cash return1% / 2% rule50% rulePrice-to-rent ratioBRRRR strategy70% rule / flippingHouse flippingMortgage affordabilityDeal screener
Returns

Rental yield

Gross and net yield — the simplest measure of a rental property's return. Net yield accounts for expenses and gives you a real-world number.

Gross rent/yr
$24,000
Annual expenses
$7,200
Gross yield
8.00%
Net yield (cap rate)
5.60%
Monthly cash flow
$1,400
Price / annual rent
12.5x
Gross yield = annual rent / price. Net yield = (annual rent − expenses) / price — this is the same as cap rate when using NOI.
Valuation

Cap rate & NOI

Net operating income divided by property value. Cap rate is how commercial real estate is priced — understand it and you can compare apartments to offices to strip malls.

Gross income
$60,000
Operating expenses
$24,000
NOI
$36,000
Cap rate
7.20%
Implied property value at target cap rates
4%
$900,000
5%
$720,000
6%
$600,000
7%
$514,286
8%
$450,000
10%
$360,000
Cap rate = NOI / property value. Higher cap rate = cheaper relative to income (but likely riskier). A 10-cap means the property pays for itself in 10 years of NOI.
Leveraged returns

Cash-on-cash return

The most honest metric for leveraged real estate: what do you actually earn on the cash you put in, after the mortgage is paid?

Down payment
$75,000
Total cash in
$80,000
Loan amount
$225,000
Monthly mortgage
$1,422
Monthly cash flow
$203
Cash-on-cash return
3.04%
Cash-on-cash = annual pre-tax cash flow / total cash invested. Measures the return on the cash you actually put in, not the entire property value. Leverage amplifies this number.
Screening

1% / 2% rule

The back-of-napkin test: monthly rent should be at least 1% (conservative) or 2% (aggressive) of the purchase price for the deal to cash-flow.

Rule

Target monthly rent = 1% of purchase price = $2,000

1% rule target
$2,000
2% rule target
$4,000
1% rule → annual yield
12.00%
2% rule → annual yield
24.00%
The 1% rule says monthly rent should be at least 1% of the purchase price for a property to cash-flow. The 2% rule is more aggressive — rare in HCOL areas. Neither replaces a proper underwriting model.
Screening

50% rule

Another screening shortcut: over the long run, roughly half your gross rent will go to operating expenses (not including mortgage). Test it against actuals.

50% rule: expenses
$1,000
50% rule: NOI
$1,000
Monthly cash flow
$-200
Cash flow margin
-10.00%
The 50% rule is a screening shortcut: operating expenses (excluding mortgage) will eat roughly 50% of gross rent over the long term. Property management, vacancy, maintenance, taxes, insurance all add up.
Buy vs rent

Price-to-rent ratio

The metropolitan-level metric that tells you whether you should be buying or renting in a given market. Below 15, bias toward buying. Above 21, rent.

Price-to-rent ratio
15.2
Monthly mortgage
$2,023
Break-even rent
$2,793
Buying vs renting
Rent cheaper
Where your market sits
<15 Buy15–21 Neutral>21 Rent
Price-to-rent = price / annual rent. Below 15 = typically better to buy. Above 21 = typically better to rent. This is a broad rule — factor in how long you'll stay and local appreciation trends.
Strategy

BRRRR strategy

Buy, Rehab, Rent, Refinance, Repeat. The scaling engine behind many real estate portfolios. Model the numbers and see if you can pull all your cash out.

Total invested
$190,000
ARV
$280,000
Refi amount
$210,000
Cash out at refi
$20,000
Cash left in deal
$0
Cash-on-cash (post-refi)
Infinity%
Monthly cash flow
$493
Annual cash flow
$5,912
BRRRR flow
Buy
→
Rehab
→
Rent
→
Refi
→
Repeat
BRRRR: Buy undervalued, Rehab, Rent out, Refinance to pull equity, Repeat. The holy grail is pulling all cash out (infinite return) while the property still cash-flows after refi.
Flipping

70% rule / flipping

The classic flipper's formula: never pay more than 70% of the after-repair value minus repair costs. Adjust the percentage and see how it changes your max offer.

Variation
ARV
$350,000
Repair costs
$50,000
70% of ARV
$245,000
Max offer (rule)
$195,000
Est. holding costs
$16,800
Max offer w/ holding
$178,200
Profit if sold at ARV
$105,000
Profit margin
30.00%
The 70% rule: max offer = 70% × ARV − repair costs. The remaining 30% (or 25% / 20%) covers profit, holding costs, closing costs, commissions, and surprises. Don't forget holding costs (taxes, insurance, utilities, interest).
Flipping

House flipping

Full flip calculator: purchase, rehab, holding costs, closing costs on both ends — and your actual profit when the dust settles.

Total project cost
$255,000
Profit
$65,000
ROI
25.49%
Annualised ROI
50.98%
Cost breakdown
Purchase
Rehab
Flipping: buy, renovate, sell. Holding costs (interest on hard money, taxes, insurance, utilities) eat profit fast. Every extra month costs roughly $1,200 — time is literally money here.
Buying power

Mortgage affordability

How much house can you afford? DTI, down payment, property taxes, insurance — the four levers that determine your budget.

Gross monthly income
$10,000
Monthly debt payments
$500
Max PITI
$3,100
Max loan (P&I only)
$369,728
Max home price
$462,160
Down payment needed
$92,432
Income allocation (front-end DTI)
PITI: 36%Remaining: 64%
DTI (debt-to-income) = total monthly debt payments / gross monthly income. Most lenders cap at 36% for conventional, up to 43% for FHA. PITI = Principal + Interest + Taxes + Insurance.
At-a-glance

Deal screener

Enter a few numbers and get instant green/red on the key metrics: gross yield, cap rate, cash-on-cash, and the 1% rule. Your first-pass filter.

Gross yield
10.56%
≥10% threshold
Cap rate
6.86%
≥6% threshold
Cash-on-cash
4.70%
≥4% threshold
1% rule
0.88%
FAIL
Monthly cash flow
$245/mo
$2,938/yr (4.70% CoC)
Quick screener: enter a few numbers and see if the deal passes basic thresholds at a glance. Green across the board = worth a deeper look.