Free Tool

50 Percent Rule Estimator

Quick expense estimate using the classic 50% rule of thumb.

Screening

Monthly Rent ($)

Monthly Principal and Interest ($)

Estimated Monthly Cash Flow

Estimated Monthly Op Ex

How this number is calculated

Basis

Expense screening rule

Formula

estimated cash flow = monthly rent - (monthly rent x 50%) - monthly P&I

Includes

Excludes

Source

Public calculator inputs

Computed

Live from the values currently entered above

Notes

This is a rough screening heuristic, not a replacement for actual operating history.

How it works

Assume operating expenses equal 50 percent of gross rent

Subtract P&I to estimate cash flow

Use as a screen, not a substitute for real underwriting

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Related tools and terms

Frequently asked questions

Is this accurate?

It's a rule of thumb. Actual expenses can be 35 to 55 percent depending on age, PM, and Section 8.