STR Pro Forma Calculator

This article is the companion guide. Let us break down every major component of a short-term rental pro forma; what each piece is, why it matters, and how to think about it as an investor.

What Is a Short-Term Rental Pro Forma?

A pro forma is a forward-looking financial projection. In real estate, it is a document that models expected income and expenses for a property to help you evaluate whether an investment makes sense before you commit capital.

For long-term rentals, pro formas are relatively straightforward: one tenant, one monthly rent, predictable vacancy. Short-term rentals are a completely different animal. Revenue fluctuates by season, by week, sometimes by day. Expenses include categories that do not exist in traditional rental models; platform fees, city occupancy taxes, turnover cleaning, guest supplies, dynamic pricing software. And the tax treatment is fundamentally different.

This is why you cannot run an STR through a standard real estate calculator and trust the output. You need a model built specifically for how short-term rentals actually operate.

A well-built STR pro forma answers these questions:

• What is this property likely to earn, net of all fees and taxes?

• What does it cost to own and operate, fully loaded?

• What will cash flow look like in year one, year two, year three?

• How does the mortgage pay down over time, and what does that mean for my equity?

• What is a realistic return on invested capital after five years?

• If I plan to take advantage of depreciation or cost segregation, how does that potentially interact with the numbers?

Let us work through each component.

Revenue: What This Property Can Actually Earn

The starting point for any STR pro forma is projected gross revenue.

Average Daily Rate and Occupancy

Revenue is a product of two variables: your average daily rate (ADR) and your occupancy percentage. Both need to be grounded in real market data, not the best-case scenario.

For a property with no historical performance record, which covers many acquisitions, you have two reliable sources to build your revenue assumption:

Professional property manager projections. This is the gold standard. A local manager who operates in that specific market, with properties of similar size and quality, can give you a data-backed projection. I maintain relationships with STR managers across California's key markets specifically so I can pull these numbers for clients. This is not a figure pulled from a national algorithm, it is someone who knows that the 3-bedroom cabin two miles from yours grossed $108,000 last year.

Revenue comps from comparable listings. When a manager projection is not available, manually identifying three to five comparable active listings in the same market; same bedroom count, similar amenities, similar proximity to demand drivers — gives you a real-world sense of ADR and occupancy. Tools like AirDNA provide aggregated data, but reviewing actual live calendars and pricing is more instructive. Revenue comps are particularly useful when you are buying a property with no rental history, because they let you benchmark the revenue assumption against what the market is actually delivering for comparable assets.

Revenue After Fees

Gross revenue is not what you keep. The first three deductions from gross revenue are platform fees, management fees, and city occupancy taxes.

Platform fees on Airbnb's host-only fee model typically run 15.5 percent of gross. VRBO has a different structure. If you are listing on multiple platforms, model a blended average.

Management fees are typically 18 to 25 percent of net revenue after platform fees for full-service California management (if you don’t plan to self-manage). Some managers charge against gross revenue, understand the fee base when modeling.

City and county Transient Occupancy Taxes (TOT) are assessed on gross revenue and vary dramatically by jurisdiction. San Diego charges 10.5 percent. Palm Springs charges 13.5 percent. Some markets are higher. TOT is a real annual expense and it belongs in every STR pro forma without exception. Disclaimer: This is subject to change, make sure to check.

After these three deductions, a property generating $90,000 in gross revenue might deliver $54,000 to $58,000 in effective revenue before operating expenses. That delta is where many pro formas fall apart.

Operating Expenses: Nothing Gets Left Out

The second major component is the complete expense stack. Here is what belongs in every STR model:

Fixed annual ownership costs:

• Property taxes (in California, approximately 1.1 to 1.2 percent of purchase price at acquisition, subject to Prop 13 limits on future increases)

• Homeowner's insurance — STR-specific policies run meaningfully higher than standard homeowner's insurance

• HOA fees, if applicable — confirm the HOA actually permits short-term rental use before closing

• Cable and internet — fast, reliable WiFi is non-negotiable for guests and deserves its own budget line

• Utilities — even with guests paying indirectly through nightly rates, owners carry base utility costs year-round

Guest turnover costs:

• Cleaning fees — the total annual cost of all turnover cleans, not the per-stay fee charged to guests

• Supplies: toiletries, paper goods, welcome items, linen replacement

• Laundry costs, if done in-house versus sent to a service

Property maintenance:

• Routine repairs and maintenance

• Pool and hot tub service, if applicable

• Landscaping

CapEx reserve: this gets its own section below because it deserves detailed attention

Administrative:

• Accounting and bookkeeping

• STR permit and licensing fees, these are increasingly common in California and belong in the annual expense stack

• Dynamic pricing software subscriptions if you are self-managing

When you total all of this for a typical 3-bedroom California STR, you are often looking at $25,000 to $40,000 in annual operating expenses before debt service. Skipping even a few of these line items can make a marginal deal look excellent on paper.

Net Operating Income and Cap Rate

Net Operating Income (NOI) is effective revenue minus all operating expenses, before debt service. It measures how productive the property is as a business, independent of how it is financed.

Cap Rate = NOI divided by Purchase Price

NOI is also the numerator in the Debt Service Coverage Ratio (DSCR = NOI divided by Annual Debt Service), which is the key qualification metric for most STR lenders. If you are financing with a DSCR loan, the most common financing structure for STR buyers, understanding your NOI precisely is essential. For a full breakdown of how DSCR financing works for short-term rentals, read my detailed guide on DSCR loans for STRs.

Cash-on-Cash Return: Year 1, Year 2, Year 3

Cash-on-cash return (CoC) is the metric most STR investors focus on first. It measures the annual cash flow you receive relative to the total cash you have deployed into the deal.

Cash-on-Cash Return = Annual Cash Flow divided by Total Cash Invested

Total cash invested includes your down payment, closing costs, and initial furnishing and setup costs. That last number is one buyers frequently leave out of their denominator.

Why year one often looks worse than it actually is:

Year one for any STR is almost always its weakest year. New listings take time to accumulate reviews, which directly affects search ranking and booking conversion. Some startup costs; photography, first full supply order, permit fees are front-loaded. There may be a gap between closing and your first guest while you furnish and configure the property.

By year two, with a well-run and well-priced listing, occupancy stabilizes and review history drives stronger search placement. Year three often looks meaningfully stronger than year one. This is why modeling a minimum three-year window is important, year one alone can make a solid deal look mediocre.

What is a good cash-on-cash return for a short-term rental?

In California's higher-priced markets, CoC in the range of 4 to 8 percent in year two is reasonable for a well-selected property. Markets with lower acquisition costs relative to rental potential; Big Bear, Indio, and Joshua Tree can deliver 8 to 12 percent or higher in a strong year.

If a deal pencils below 3 percent CoC in year two after a proper ramp-up, I want to understand the thesis. The answer might be appreciation, but that needs to be an explicit, conscious part of the investment case, not an implied safety net.

In the full STR analysis spreadsheet we build for clients, we model three scenarios: low, medium, and high (bull case). Understanding where the deal breaks tells you exactly how much margin you have against a difficult year.

Amortization: The Wealth Builder Most Investors Ignore

Every mortgage payment has two components: interest and principal. The interest is a true expense. The principal is equity you are building - money going directly onto your balance sheet.

In the early years of a 30-year mortgage, most of the payment is interest. On a $500,000 loan at 7.25 percent, roughly $36,000 of year one's debt service is interest, while approximately $2,500 goes toward principal reduction. By year five that principal paydown has grown. By year ten it accelerates considerably.

Why amortization belongs in your total return model:

Most investors evaluate an STR on cash flow alone. But your true annual return has three components working simultaneously:

1. Cash flow after debt service

2. Principal paydown (equity accumulation through amortization)

3. Property appreciation

A property generating $6,000 in annual cash flow, paying down $3,000 in principal in year one, and appreciating 4 percent on a $650,000 purchase — adding $26,000 in equity — has delivered approximately $35,000 in total economic return that year. The cash-on-cash metric captures only $6,000 of that.

This is why I always present clients with a total return model alongside the cash flow model. The full STR analysis spreadsheet maps out the amortization schedule year by year, so you can see your equity position building from both debt reduction and appreciation simultaneously, not just from cash flow.

The Tax Dimension: Depreciation and Cost Segregation

I am going to keep this section intentionally brief, because the details require a qualified CPA's guidance — not an article (like the one you’re reading).

The short version: short-term rentals can be extraordinarily tax-efficient. Depreciation allows you to deduct the cost of the structure over its useful life, creating paper losses that may offset other income. Cost segregation can accelerate a significant portion of that depreciation into year one and year two, amplifying the benefit dramatically. And when an STR owner materially participates in the property's operations, those losses may be usable against ordinary income — potentially including W-2 income.

The potential tax benefit of an STR investment is real, significant, and entirely separate from cash flow. It does not appear in your pro forma's bottom line. It appears in your tax return. But it is a meaningful part of the complete investment picture for buyers who qualify.

For the full breakdown on how both of these strategies work, I have written in depth on the topic:

Read: Cost Segregation for Short-Term Rentals — Full Guide

Read: Material Participation for Short-Term Rentals — Full Guide

The note for your pro forma: if you intend to pursue cost segregation or rely on depreciation as part of your investment thesis, flag it explicitly in your model and confirm eligibility with your CPA before closing.

CapEx: The Number That Breaks Underprepared Investors

Capital expenditure refers to large, irregular replacement expenses: a new HVAC system, a water heater, a roof, appliances, hot tub equipment, or a full furniture refresh. Unlike a $200 plumbing repair, a CapEx event might be $10,000 to $20,000 and it arrives without a scheduled warning.

The most common mistake I see on STR pro formas: CapEx is completely missing.

The investor models revenue, models expenses, feels good about the numbers and then 18 months in, the HVAC fails. Sixteen thousand dollars walks out the door, and the deal that looked solid on paper suddenly does not.

How to model CapEx properly:

The standard approach for STR CapEx reserve is 3+ percent of gross revenue held back annually. On a property grossing $85,000, that is $2,550 to $4,250 per year set aside into a reserve account. You will not spend it every year. But in the year you need a new HVAC or a full appliance replacement cycle, you will be grateful it is there.

STR-specific CapEx items to plan for:

• Appliances — STR appliances take more use than primary-home appliances. Plan for 5 to 7 year replacement cycles on dishwashers, washers, and dryers.

• HVAC systems — the single most expensive surprise in short-term rental ownership. During due diligence, age the existing system carefully.

• Mattresses — in a high-occupancy STR, plan for a 3 to 5 year replacement cycle per bed.

• Furniture and furnishings — sofas, dining chairs, and outdoor furniture all degrade faster in a rental setting than a primary home.

• Hot tub and pool equipment — pumps, heaters, and jets fail. Budget $800 to $1,500 per year in reserve if the property has a hot tub.

• Exterior and roof — for properties over 10 years old, factor painting cycles and roofing age into your due diligence and reserve planning.

In the full STR analysis spreadsheet we build for clients, CapEx reserve is a dedicated line item.

5-Year Appreciation: The Complete Return Picture

Cash flow matters. But for most California STR investors, appreciation is the primary wealth driver over a five-year hold.

In markets like Joshua Tree, Indio, Big Bear, coastal San Diego, Lake Tahoe adjacents, and Palm Springs, the property you buy today is very likely worth meaningfully more in five years. That equity compounds alongside the rental income it produces.

Conservative appreciation modeling:

We use 2 to 4 percent annual appreciation for established California STR markets, depending on the specific location and market dynamics. That is conservative by California's historical standards for coastal and resort markets, but we prefer to estimate conservatively and have our clients be pleasantly surprised rather than disappointed.

What 3 percent annual appreciation looks like on a $650,000 purchase:

Year Property Value Cumulative Gain

• Year 1: $676,000 -> $20,280

• Year 2: $696,280 -> $41,168

• Year 3: $717,168 -> $62,683

• Year 4: $738,683 -> $84,843

• Year 5: $760,844 -> $107,669

Over five years, that is approximately $107,669 in potential equity growth from appreciation alone, on top of cash flow generated and principal paid down. When you consider that this is achieved with a 25 percent down payment of $162,500, the return on invested equity becomes substantial.

The critical caveat: Appreciation is real, but it is unrealized until you sell or refinance. It should never be used to justify a property that cannot cover its operating expenses. Cash flow and DSCR tell you whether you can afford to hold the property. Appreciation is the reason you want to hold it for as long as possible.

The Full STR Analysis Spreadsheet: What We Build for Clients

The interactive pro forma calculator on this page is a screening tool. It is excellent at helping you quickly assess whether a property is worth pursuing. But when a client is seriously evaluating a purchase and we are in the due diligence phase, we build a full STR analysis spreadsheet in Excel that goes considerably further.

Here is what is inside:

Three-year cash flow projection. Year-by-year cash flow through year three, with assumptions for modest revenue growth; typically 2 to 3 percent annually as the listing matures and realistic expense growth.

Complete amortization schedule. Annual principal paydown shown explicitly alongside interest expense, so you can see exactly how equity is building through debt reduction every year.

Depreciation and cost segregation estimate. Not a CPA opinion; a planning figure that models what the depreciation benefit could look like if you pursue a cost segregation strategy, so you can have an informed conversation with your tax advisor about whether it makes sense for your situation.

Scenario analysis. Three columns: low case, medium case, and high case. You can see exactly where the deal breaks and how much cushion exists against a weak year.

This is not a template I publish publicly. It is built specifically for each property using real estimated projections, market data, and property-specific due diligence. If you are seriously evaluating a California STR acquisition and want us to represent you in your next acquisition, then click the link below:

Request a full STR analysis — schedule a consultation with Josh and Kailen

How to Use the Calculator on This Page

The STR Pro Forma Calculator updates in real time as you adjust inputs. A few tips for getting the most out of it:

Start conservative on revenue.

Fill in every expense line. Do not skip CapEx reserve, city taxes, cable and internet, or supplies. The calculator is only as accurate as the inputs you give it.

Watch the verdict indicator. Green means solid positive cash flow with healthy returns. Yellow means marginal — the deal may work but you are relying on appreciation or tax benefits to carry it. Red means the numbers don’t look good at these assumptions.

Stress-test, do not just project. Drop occupancy 10 percentage points. Drop ADR 10 percent. See what happens to cash flow. That sensitivity exercise is often more instructive than the base case projection.

Know what the calculator does not show. It does not model seasonal revenue variation, amortization, appreciation, or the tax dimension. Those go into the full analysis spreadsheet and available if you work with us.

The Bottom Line

The investors who consistently make good STR acquisitions are not necessarily smarter than the ones who make bad ones. They are more disciplined. They refuse to let optimism drive their decision. They model every expense. They stress-test assumptions. And they understand that numbers on paper are a starting point for a conversation with a property manager, a CPA, and a lender: not the end of the analysis.

The calculator on this page gives you a structured starting point. The full STR analysis spreadsheet gives you the complete picture. The conversation we have is where we figure out whether a specific property in a specific market actually makes sense for your situation.

If you are evaluating a short-term rental purchase in California or trying to understand whether the asset class is right for you… let chat!

Schedule a free consultation with Josh and Kailen