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50% Rule Calculator

Estimate net operating income (NOI) in seconds. The 50% rule assumes operating expenses run about half of gross rent — a fast way to triage rental properties before pulling actual tax and insurance numbers.

Property Details

The 50% rule estimates that operating expenses run about half of gross rent — before mortgage payments.

$
$

Add price to see an implied cap rate.

Estimated NOI

$13,200

estimated NOI per year

Gross Income
$26,400
/year
Op. Expenses
$13,200
≈ 50% of rent
Monthly NOI
$1,100
before debt
Implied Cap Rate
4.80%
NOI ÷ Price
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What is the 50% rule?

The 50% rule is a quick estimate: roughly half of a rental property’s gross rent will be eaten by operating expenses (taxes, insurance, maintenance, vacancy, capex, management). What’s left is your estimated NOI — the cash you have to cover the mortgage and produce profit.

The formula

NOI ≈ Gross Annual Rent × 50%
Operating expenses include taxes, insurance, maintenance, capex, vacancy, and management — but NOT the mortgage payment.

When 50% is too low

  • Older properties with deferred maintenance.
  • High-tax states (NJ, IL, NY, TX) where property tax alone is 2–3% of value.
  • Class C/D rentals with higher turnover and tenant damage.
  • Single-family homes managed by a property manager (10% of rent off the top).

When 50% is too high

  • New construction in low-tax states (FL, TN, NV).
  • Self-managed rentals with no management fee.
  • Multifamily where economies of scale spread fixed costs.

Frequently asked questions

What is the 50% rule in real estate?

The 50% rule says about 50% of a rental property’s gross rent will go to operating expenses (taxes, insurance, maintenance, vacancy, capex, management) before mortgage payments. The remaining 50% is your estimated NOI.

What does the 50% rule include?

It includes everything except principal and interest on a mortgage: property taxes, insurance, maintenance, repairs, capital expenditures, vacancy loss, and property management. It does NOT include the loan payment itself — NOI is unlevered.

Is 50% accurate for operating expenses?

It’s a rough average. Newer properties in low-tax states with low vacancy can run 30–40%. Older Class C/D properties in high-tax states with high turnover can run 55–65%. Use 50% as a starting point and refine with actual taxes, insurance, and historical operating data.

How is the 50% rule different from the 1% rule?

The 1% rule screens whether rent is high enough relative to price (rent ÷ price ≥ 1%). The 50% rule estimates how much of that rent will survive after expenses. They’re complementary: 1% rule for the price-to-rent screen, 50% rule for the rough NOI estimate.

Can I use the 50% rule for multifamily and commercial?

Yes — and many commercial pros use it as a sanity check on operating expense ratios. For larger multifamily, 40–50% is typical. For NNN commercial leases, expenses are passed through to the tenant, so the ratio is much lower (10–15%).

Why does the 50% rule exist if you can just calculate real expenses?

For triage. When you’re screening 20+ properties, you don’t have time to pull actual taxes and insurance quotes for each one. The 50% rule gets you to a rough cash-flow estimate fast so you can rule out non-starters and spend your detailed underwriting time on the survivors.

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