Free calculator

STR Cash Flow Calculator: month by month and DSCR

Enter the purchase and the nightly rate. See cash flow for each month of the year, the reserve the slow months need, and your DSCR.

No account neededFree PDF report

Examples computed by this calculator on sample inputs. Not market data.

The deal in four numbers

  • No account needed
  • Airbnb fees per Help Center article 1857
  • Every formula shown, sources dated
  • Free PDF report with every chart
How it works

Three steps. About a minute.

  1. Step 1: Enter the deal

    Price, nightly rate, occupancy and the shape of your season. The loan and cost lines start on a sample you can edit.

  2. Step 2: See every month

    Cash flow for each calendar month, the running balance, the reserve you need, and DSCR the way lenders read it.

  3. Step 3: Keep the PDF

    Download the twelve-month table, the cash balance chart and the lender view to take to your broker.

Your report

What you'll get

Seasonal reserve neededFrom the sample
THE HEADLINE

The cash you need on hand for the slow stretch

Running cash flow from the month you take over, and the deepest point it reaches. That low point is the reserve, and it needs to be in the account before the first slow month.

  • Seasonal reserve needed
  • Months with negative cash flow
  • Worst and best month

Showing part 1 of 5: Reserve needed

  • Cash flow for every month, with real day counts
  • The reserve your slowest stretch needs
  • Months your reserve lasts with no bookings at all
  • DSCR against your lender minimum, and the largest loan
  • Five years of cash flow with rate growth and inflation

A year that breaks even can still drain your account

Monthly cash flowFrom the sample

Annual cash flow averages the good months against the bad ones. The account the mortgage comes out of does not. In a summer market the winter months can run negative one after another, and the mortgage is due every one of them.

This calculator runs each month on its own day count and its share of your occupancy and rate, so you see which months lose money and how deep the hole gets before the season pays it back.

Cash flow mistakes this calculator catches

A door can be roughly break-even over a year and still run your account dry in February. These are the gaps the 12-month view exposes.

  1. 01Sizing the reserve from the annual figure

    The sample door loses $250 over the year, which sounds trivial. Seven of its twelve months are negative, and the worst, February, loses $1,604.

  2. 02Ignoring the month you start

    The same door needs $250 of reserve if you take it over in May and $8,030 if you take it over in October. The start month changes the reserve by 32x.

  3. 03Quoting the lender's DSCR to yourself

    A lender reading gross over PITIA sees 1.93 on the sample door. Its NOI only covers the loan 0.99 times. The lender ratio gets you the loan; NOI DSCR tells you whether you can carry it.

  4. 04Forgetting a no-booking month

    With bookings at zero, $3,307 of fixed costs and loan payment still leave each month. A $5,000 reserve covers about six weeks.

Size the reserve from the low point

Cash balance through the yearFrom the sample

Add up monthly cash flow from the month you take over the property. The deepest point that running total reaches is the cash you need on hand to get through the slow stretch without topping up from somewhere else.

That covers the seasonal dip only. Keep a separate emergency reserve for a broken boiler or a cancelled month. Buying just before the quiet season needs more cash than buying before the peak. Once you own it, MagicBNB's Property Detail view flags each year's best and worst month.

What good looks like

Two readings decide whether a door's cash flow is safe to carry.

OutputWeakOkayGood
Months with negative cash flowRule of thumb used by this calculator's verdict.6 or more3 to 50 to 2
NOI DSCRRule of thumb used by this calculator. Lenders set their own minimum, often 1.0 to 1.25.Under 1.01.0 to 1.251.25 or more
Reserve against the seasonal lowRule of thumb. The extra month covers a repair or a cancellation run.Below the low pointCovers the low pointCovers the low point plus a month of fixed costs

DSCR: the test a lender runs, and the one you should

From the sample

Your test

The stricter view
NOI over debt service
0.99

A common lender test

Gross over PITIA
1.93
Payout over PITIA
1.63

DSCR is NOI divided by debt service. Under 1.0, the property does not cover its own loan. Many STR lenders divide gross revenue or payout by PITIA instead (principal, interest, tax, insurance and HOA), which reads higher. A deal can pass the lender test and still lose money.

Run your own test on NOI before you sign. Treat the lender figure as the bar for getting the loan, and the NOI figure as the bar for keeping the property.

How operators use it

  1. Buyer choosing a closing date

    Can close in September or push to April on a summer-peak beach property.

    Runs both start months, sees the autumn close needs several thousand more in reserve, and plans the cash before signing.

  2. Operator refinancing into a DSCR loan

    Lender quotes a 1.0 minimum and the payout ratio looks healthy.

    Checks NOI DSCR and the largest loan at that minimum, and pays down enough at closing to keep NOI covering the debt.

STR cash flow, month by month

Why does my Airbnb run out of cash in winter?

Because fixed costs and the mortgage arrive every month and bookings do not. The sample loses money in 7 of 12 months, worst in February at -$1,604, while the full year ends only $250 down.

An annual figure averages the summer surplus against the winter shortfall. Your bank account does not average; it runs in order. If the slow months come first, the account has to carry them until the summer pays them back.

The 12-month table shows that order. Read the cumulative column: its lowest point is the most cash the property will ask of you, and the month it lands is when you need it.

Sample property, starting in January
  • January$3,042 gross, $4,644 total cost incl. debt, -$1,602
  • February-$1,604, running total -$3,206
  • April-$617, running total -$4,745 (the low point)
  • July+$2,883, running total back to +$617
  • Decemberyear ends at -$250

What is the best month to buy a short-term rental?

The month just before your peak season, if you can choose. The sample needs a $250 reserve when taken over in May and $8,030 when taken over in October.

The property and the year's total are identical in both cases. Only the order of the months changes. Starting in May, the first months are the profitable ones and they fund the winter. Starting in October, you meet seven losing months before the first good one in May.

If the closing date is fixed, size the reserve for it. If it is not, the start month is one of the cheapest levers in the whole purchase.

Seasonal reserve needed, same property, different start months
  • Take over in January$4,745
  • Take over in May$250
  • Take over in October$8,030

How do lenders calculate DSCR on an Airbnb?

It depends on the lender. Some divide gross rent by PITIA, some use payout, and the conservative test is NOI over debt service. On the sample those read 1.93, 1.63 and 0.99.

PITIA is the monthly housing payment: principal, interest, property tax, insurance and HOA dues. Dividing gross booking revenue by it ignores the platform fee, the cleaner and every operating cost, so it flatters an STR more than any other ratio.

The lender's ratio decides whether you get the loan. NOI DSCR decides whether you can carry it. The sample passes a lender reading of 1.93 while its operating income covers the loan only 0.99 times.

Sample property, three DSCR readings
  • PITIA$2,207 P&I + $425 property tax + $250 insurance = $2,882 a month
  • Gross booking revenue / PITIA$5,567 / $2,882 = 1.93
  • Net payout / PITIA1.63
  • NOI / debt service$26,233 / $26,484 = 0.99

How much do I need to pay down to meet a DSCR minimum?

The loan has to shrink until NOI covers its payments at the minimum. On the sample, a 1.00 minimum allows a $315,736 loan against the $318,750 planned, so $3,014 more down.

The calculation holds the rate and term and solves for the loan amount. A small shortfall like the sample's is a few thousand dollars at closing. A large one means the price is wrong for the income, and the valuation calculator is the better tool.

The same table shows the occupancy that would meet the minimum without paying down: 59.8% on the sample, against the 59.5% expected.

Where it fits in your year

  1. Before closing

    Enter the start month you expect and the reserve you plan to hold. If the balance line crosses zero, raise the reserve or move the date.

  2. Each autumn

    Rerun it with this year's real monthly rates before the slow season. Top up the reserve to the low point before November.

  3. Every week after

    Track the real balance. MagicBNB's Cash position card shows combined cash across connected accounts after every bank sync.

Terms on this page

Seasonal reserve
The cash needed to get from your start month to the year's lowest running balance.
DSCR
Debt service coverage ratio: NOI divided by the annual loan payments.
PITIA
Principal, interest, taxes, insurance and association dues: the monthly housing payment a lender counts.
Runway
How many months your reserve covers fixed costs and the loan with no bookings at all.
Payback
Years for cumulative cash flow to return the cash you put in.

Questions

How do you calculate cash flow on an Airbnb?

For each month, take gross booking revenue and subtract the platform fee, every operating cost and the full mortgage payment. Do it month by month with real day counts rather than once on the annual average, because the average hides the months that drain your account.

What DSCR do lenders want for a short-term rental loan?

It varies by lender. Many lender guides describe 1.0 as a floor, with 1.10 to 1.25 for better pricing. Many STR lenders divide gross or net booking income by PITIA, which reads higher than NOI over debt service, so a deal can pass a lender test and still lose money. Ask your lender which version they use.

What is the difference between cash flow and profit?

Cash flow is what is left after the full mortgage payment, principal included. Pre-tax profit counts only the interest, because principal is equity, and adds back an unspent capex reserve. A door can show a profit and negative cash flow in the same year.

How much cash reserve should an STR hold?

At least the deepest point the running total of monthly cash flow reaches from the month you buy, which this calculator reports as reserve needed. That covers the seasonal dip only. Keep a separate emergency reserve for repairs and empty months on top of it.

How do slow months change annual cash flow?

They do not change the annual total, but they change when you need the cash. In the sample the year ends near zero while seven months are negative, so the owner needs several thousand dollars on hand before summer pays it back.

How long would my reserve last if bookings stopped?

Divide the reserve by what the property costs in a month with no guests: fixed costs (insurance, property tax, utilities, software, HOA) plus the loan payment. The results show that runway in months, and how much is left once the seasonal low point has taken its share.

Is negative cash flow on an Airbnb ever acceptable?

Only if you planned for it and can fund it. Some buyers accept a small negative to hold a property for appreciation. That is a bet on the price, with the STR income only softening it.

What is PITIA?

Principal, interest, taxes, insurance and association dues: the monthly housing payment most lenders measure income against. On the sample it is $2,882 a month.

Does STR cash flow include depreciation?

No. Depreciation is a tax deduction, not money leaving your account. Cash flow is NOI minus the full loan payment; the tax calculator handles depreciation.

Should a capex reserve count against cash flow?

Yes, in this calculator. Furniture, appliances and roofs wear out on a schedule, and setting money aside monthly is cheaper than finding it all at once.

What does Lender DSCR, payout / PITIA mean?

Net payout after the platform fee divided by the monthly housing payment. It sits between the generous gross reading and the strict NOI reading.

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Formulas last checked .

Cash position

Watch the real balance

This calculator projects a year of balances. MagicBNB's Cash position card shows combined cash across every connected account, updated with each bank sync, so you see a low account before an autopay bounces.

Two more places this shows up in MagicBNB

  • Bank account integrationChecking, savings, business and merchant accounts link with real-time sync, so the reserve you planned is the reserve you can see.
  • Property DetailMonth-by-month results per door with the best and worst month highlighted, which is the seasonal shape this calculator assumes, measured.
See live cash across accounts
Go deeper

Run your cash flow live, month by month

This calculator is the quick look at the year you expect. MagicBNB runs the same numbers in depth and in real time, property by property, in its Portfolio Overview.

Run the numbers in depthBack to the calculator