AtlasCalcsUtility Calculation Suite
2026-09-21 7 min read

Real Estate Cash Flow Calculator

The monthly and annual cash flow after every expense and the mortgage for a property. Live calculator with worked steps and charts.

Calculator

Purchase Price Help
$

The price you pay, before closing costs.

Down Payment(%) Help
%

Investment loans typically require 20–30% down.

Interest Rate(%)
%
Loan Term(years)
years
Repair / Rehab Budget
$
Monthly Rent Help
$

Gross scheduled rent before vacancy.

Vacancy & Credit Loss(%) Help
%

Share of scheduled rent lost to turnover and non-payment.

Property Tax (Annual)
$
Insurance (Annual)
$
Maintenance & Repairs(%) Help
%

Share of effective income budgeted for repairs.

Property Management(%) Help
%

Share of collected rent charged by the manager.

Holding Period(years)
years
Advanced options (5)
Closing Costs
$
Other Monthly Income Help
$

Laundry, parking, storage, late fees, pet rent.

Utilities (Annual, Landlord-Paid)
$
Other Expenses (Annual)
$
Rent Growth(%)
%

This property calculator runs on a full rental pro-forma: rent is annualised and reduced by vacancy, every operating expense is itemised to reach NOI, and the loan amortises monthly at the rate entered. Results update live as you type.

Amortization schedule

Balance Interest Payment
View:
YearInterestPrincipalEnding Balance
1$15,677.60$2,285.57$222,714.43
2$15,512.37$2,450.80$220,263.63
3$15,335.20$2,627.96$217,635.67
4$15,145.23$2,817.94$214,817.73
5$14,941.52$3,021.65$211,796.08
6$14,723.08$3,240.08$208,555.99
7$14,488.86$3,474.31$205,081.68
8$14,237.70$3,725.47$201,356.21
9$13,968.38$3,994.78$197,361.43
10$13,679.60$4,283.57$193,077.86
11$13,369.94$4,593.23$188,484.64
12$13,037.90$4,925.27$183,559.37
13$12,681.85$5,281.32$178,278.05
14$12,300.06$5,663.11$172,614.94
15$11,890.68$6,072.49$166,542.45
16$11,451.69$6,511.47$160,030.98
17$10,980.98$6,982.19$153,048.79
18$10,476.24$7,486.93$145,561.86
19$9,935.01$8,028.16$137,533.69
20$9,354.65$8,608.52$128,925.18
21$8,732.34$9,230.83$119,694.35
22$8,065.04$9,898.13$109,796.22
23$7,349.50$10,613.66$99,182.56
24$6,582.24$11,380.93$87,801.63
25$5,759.51$12,203.65$75,597.98
26$4,877.31$13,085.86$62,512.12
27$3,931.33$14,031.83$48,480.29
28$2,916.97$15,046.20$33,434.09
29$1,829.28$16,133.89$17,300.21
30$662.96$17,300.21$0.00

Results

Optimal

Monthly Cash Flow

$285

Annual Cash Flow

$3,424

Net Operating Income

$21,387

Annual Debt Service

$17,963

Effective Gross Income

$29,640

Operating Expenses

$8,253

Expense Ratio

27.84%

Vacancy Loss

$1,560

Cumulative Cash Flow at Sale

$65,544

After-Tax Yield (with depreciation shield)

5.28%

Live results update as you type — currently showing monthly cash flow of $285. Replace the defaults with your own rent roll, tax bill and insurance quote for an exact comparison.

Visualizations

Annual Cash Flow Over the Hold

3,424Y1
4,065Y2
4,726Y3
5,407Y4
6,108Y5
6,830Y6
7,574Y7
8,340Y8
9,129Y9
9,942Y10

Where the Effective Income Goes

Operating expenses26%
Vacancy & credit5%
Debt service58%
Cash flow11%

Cumulative Cash Flow

Formula

Annual cash flow is what remains of net operating income after the mortgage is paid; dividing by twelve expresses it as the monthly figure most investors budget around.

Cash flow = NOI − Annual debt service; Monthly cash flow = Cash flow ÷ 12

Alternative Form

NOI = EGI − Operating expenses

Variables

SymbolNameUnitDescription
NOINOI$/yrIncome left after operating expenses
DSDebt service$/yrAnnual mortgage payments
CFCash flow$/yrNOI minus debt service

Explanation

Positive cash flow means the tenant services the debt and pays you to own the asset; negative cash flow means you pay monthly for the privilege of holding it.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Size the loan from the purchase price and the down payment.

Loan = price × (1 − down payment %)
Purchase price:$300,000
Down payment:25.00%
Intermediate: $300,000 × (1 − 0.25)
Result: $225,000 loan, $75,000 down
Step 2

Amortise the loan to find the monthly payment and annual debt service.

P = L × i ÷ (1 − (1 + i)^−n)
Loan:$225,000
Rate:7.00%
Term:30 years
Intermediate: i = 0.005833333333333334 per month, n = 360 payments
Result: $1,496.93/month ($17,963/year)
Step 3

Annualise the rent and deduct vacancy and credit loss.

EGI = (rent × 12 + other income) × (1 − vacancy %)
Monthly rent:$2,600.00
Vacancy:5.00%
Intermediate: $31,200 − $1,560
Result: $29,640 effective gross income
Step 4

Subtract every operating expense to reach net operating income.

NOI = EGI − taxes − insurance − maintenance − management − utilities − other
Effective income:$29,640
Operating expenses:$8,253
Intermediate: $29,640 − $8,253
Result: $21,387 NOI
Step 5

Compute cash flow from the figures above.

Cash flow = NOI − annual debt service
NOI:$21,387
Debt service:$17,963
Cash invested:$89,000
Intermediate: Cash flow = $3,424 per year
Result: $3,424 per year
Final Answer
$285

Worked Examples

See how the calculator works with different scenarios.

Scenario

The real estate cash flow calculator run on the values above, showing the full calculation path rather than only the answer.

Inputs

Price:300000
Rent Monthly:2600
Down Payment Pct:25
Rate:7

Calculation

1. Size the loan from the purchase price and the down payment. → $225,000 loan, $75,000 down 2. Amortise the loan to find the monthly payment and annual debt service. → $1,496.93/month ($17,963/year) 3. Annualise the rent and deduct vacancy and credit loss. → $29,640 effective gross income 4. Subtract every operating expense to reach net operating income. → $21,387 NOI 5. Compute cash flow from the figures above. → $3,424 per year

Result

Monthly Cash Flow: $285

Interpretation

Effective income $29,640 less $8,253 of operating expenses gives $21,387 of NOI; $17,963 of debt service leaves $3,424 a year ($285.30 a month).

Understanding Your Result

Your Result: Monthly Cash Flow: $285

Typical range: Positive cash flow usually means operating expenses of 35–45% of effective income with a payment below $1,782 a month; this deal models at 27.84% expenses and a $1,496.93 payment.

What This Means

Positive cash flow means the tenant services the debt and pays you to own the asset; negative cash flow means you pay monthly for the privilege of holding it.

Why It Matters

Effective income $29,640 less $8,253 of operating expenses gives $21,387 of NOI; $17,963 of debt service leaves $3,424 a year ($285.30 a month).

Professional Interpretation

Effective income $29,640 less $8,253 of operating expenses gives $21,387 of NOI; $17,963 of debt service leaves $3,424 a year ($285.30 a month).

How this is calculated

Annual cash flow is what remains of net operating income after the mortgage is paid; dividing by twelve expresses it as the monthly figure most investors budget around.

What drives the result

The pro-forma method: annualise the rent, deduct vacancy to reach effective gross income, subtract operating expenses to reach net operating income, then subtract debt service to reach cash flow. Each layer answers a different question — value (cap rate), lender safety (DSCR) and investor return (cash-on-cash).

Recommendations

  • •Cash flow is what the property produces after a reserve, not what is left if you skip one — fund maintenance and vacancy first.
  • •Compare the monthly figure against a capital-expenditure reserve of about 5% of rent before calling the deal positive.

Educational Content

Introduction

Rental analysis starts with one year of operations: scheduled rent, vacancy and credit loss, every operating expense, and the debt payment. NOI is what remains for the owner; everything else — cap rate, cash flow, DSCR, cash-on-cash — is NOI viewed from a different angle.

Concept Explanation

The pro-forma method: annualise the rent, deduct vacancy to reach effective gross income, subtract operating expenses to reach net operating income, then subtract debt service to reach cash flow. Each layer answers a different question — value (cap rate), lender safety (DSCR) and investor return (cash-on-cash).

Applications

▸Screening a listing against your price and return requirements in minutes
▸Comparing two or three candidate properties on the same pro-forma assumptions
▸Preparing a lender-ready one-year operating statement for a loan request
▸Setting rents and budgeting expenses for a property you already own

Benefits

  • •One consistent model across every property, so comparisons are fair
  • •Forces every expense to be named and budgeted rather than ignored
  • •Separates the property’s performance from the financing around it

Limitations

  • •A one-year pro-forma cannot capture capital expenditures that arrive in lumps — roofs, systems and exteriors need their own reserve
  • •Actual vacancy and expense ratios vary by market and management quality; a single assumption hides that spread
  • •The model assumes the rent roll is at market; in-place rents below market flatter the deal

Best Practices

  • •Build the pro-forma from your own quotes — insurance, taxes and management — not the seller’s summary
  • •Stress the deal: rent down 5%, vacancy up 5% — if it still pays, it will survive a soft year
  • •Fund a capital-expenditure reserve of about 5% of rent before calling any cash flow "positive"

Common Misconceptions

Myth: NOI is the profit the owner pockets.
Truth: NOI comes before the mortgage payment; only cash flow (NOI − debt service) reaches the owner’s bank account.
Myth: A property with positive cash flow is always a good deal.
Truth: Positive cash flow on an overpriced building can still be a worse investment than the same cash in an index fund — compare returns, not just sign.
Myth: Operating expenses are optional line items.
Truth: Vacancy, maintenance and management are real costs even when self-managed; underwriting them at zero inflates the price you can justify.

Practical Tips

  • •Budget a capital-expenditure reserve alongside cash flow — a positive number with no reserve is optimistic
  • •Watch the expense ratio: sustained 45%+ usually signals mispriced management or utilities

Common Mistakes

Counting principal paydown as cash flow.
Principal reduction builds equity, not spendable cash — the two move on different timelines.
Assuming rent never dips.
Model one turnover-and-downtime event per year; the vacancy input exists for exactly that.

Assumptions

This calculator makes the following assumptions to provide estimates:

Level debt service: The mortgage payment is constant for the whole year.
Point-in-time rent: The rent entered is assumed collected for all twelve months less vacancy.

Limitations

Be aware of these limitations when using this calculator:

Limitation: A one-year pro-forma cannot capture capital expenditures that arrive in lumps — roofs, systems and exteriors need their own reserve
Limitation: Actual vacancy and expense ratios vary by market and management quality; a single assumption hides that spread
Limitation: The model assumes the rent roll is at market; in-place rents below market flatter the deal

Frequently Asked Questions

Answers to common questions about this calculator.

How much cash flow per door is enough?
Rules of thumb ($100–$200 per unit) are market-dependent; the durable test is cash-on-cash return versus your next-best use of the same cash.
Who uses the real estate cash flow calculator?
It is used by rental investors screening and pricing deals, by owner-operators budgeting expenses and rents, and by agents, lenders and advisers sanity-checking the numbers before money moves. It sits in the Returns & Metrics group of the Real Estate Investing section of Atlascalcs.
How accurate is the real estate cash flow calculator?
Every figure follows from the inputs using standard property underwriting mathematics, so it is accurate to the quality of the values you enter. Lenders, appraisers and tax assessors each apply their own adjustments, so expect small differences against formal documents.
Do I need to sign up or pay to use this calculator?
No. Every Atlascalcs calculator is free, runs entirely in your browser and never asks for an account. Nothing you enter is uploaded or stored.
Can I use these numbers in a formal valuation or loan application?
The calculator is an underwriting aid, not an appraisal or a lender offer. Lenders and appraisers apply their own adjustments, so treat the output as a disciplined estimate to bring to those conversations.
How do I choose realistic inputs?
Pull rent from comparable leases, property tax from the current assessment, insurance from a quote, and management and maintenance from what operators in your market actually pay. Seller pro-formas are marketing documents.

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Related Guides

Deepen your understanding with these educational resources.

Glossary

Technical terms used in mortgage calculations explained in plain language.

Net Operating Income (NOI)
Effective gross income minus operating expenses, before debt service and income tax. The core measure of a property’s earning power.
Effective Gross Income (EGI)
Scheduled rent plus other income, less vacancy and credit loss.
PITI
Principal, interest, property taxes and insurance — the full monthly housing payment.
Vacancy and Credit Loss
The share of scheduled rent never collected, from turnover, downtime and non-payment.

Authoritative References

Trusted sources and standards referenced by this calculator.

Applicable Standards

Level-payment amortisation, payments assumed in arrearsIncome and expenses annualised; percentages entered as annual ratesStraight-line depreciation per IRC §168 recovery periodsMoney rounded for display only; all calculations run at full precision

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Page Information

Last Updated:

2026-09-21

Version:

2.0.0

License:

Free to use for educational and professional purposes.