Free deal calculators
Run your numbers like your bookkeeper would
Nine calculators, the same math we run for clients. Free, no signup. Results update as you type. Estimates only: verify every deal with your own numbers, your lender, and your CPA.
Deal inputs
Flip economics
updates live| Loan amount | — |
|---|---|
| Cost of money (points + interest) | — |
| Holding costs | — |
| Selling costs | — |
| All-in project cost | — |
| Net profit | — |
| Cash invested | — |
| ROI on cash | — |
| Annualized ROI | — |
| 70%-rule max offer (MAO) | — |
The month-to-month version of this math (budget vs. actual per phase, draw tracking) is in the free Flip Profit Calculator spreadsheet.
Your books should show this P&L per project, in real time — not at tax season. If yours can’t, that’s fixable.
Book a diagnosticProperty inputs
Rental economics
updates live| Monthly debt service (P&I) | — |
|---|---|
| NOI (annual) | — |
| Cap rate | — |
| Monthly cash flow | — |
| Cash-on-cash return | — |
| 1% rule check | — |
NOI = income after vacancy, management, repairs, taxes, insurance, HOA. Before debt service and CapEx reserves. Cash flow subtracts both.
Per-property cash flow like this, every month, straight from clean books. That’s the whole service.
See pricingProject inputs
BRRRR economics
updates live| Total project cost | — |
|---|---|
| Refi loan (cash back at refi) | — |
| Cash left in deal | — |
| Equity position after refi | — |
| New monthly payment (P&I) | — |
| Monthly cash flow | — |
| Cash-on-cash return | — |
If the refi returns all your cash, cash-on-cash is effectively infinite. The deal recycles your capital into the next one. That’s the whole strategy.
Refi lenders want seasoned, clean rental financials. Get your books lender-ready before you apply, not the week the appraisal lands.
Book a diagnosticLoan inputs
True cost of money
updates live| Points | — |
|---|---|
| Monthly interest | — |
| Total interest over hold | — |
| Total cost of money | — |
| Carry per month held | — |
| Effective annualized cost | — |
Every month of hold costs you the carry number, that’s why budget slips are profit killers. In your books, all of this belongs in project holding costs, not “bank fees.”
If your cost of money is buried in “bank fees,” your flip profit is a guess. We split it out per project so it isn’t.
Book a diagnosticProperty & loan inputs
Debt service coverage
updates live| Monthly NOI | — |
|---|---|
| Monthly debt service (P&I) | — |
| DSCR | — |
| Verdict at required DSCR | — |
| Max loan at required DSCR | — |
Lenders compute DSCR from your books, not your memory. Clean per-property financials are what make this number provable. that’s our whole job.
Need DSCR-ready financials a lender won’t kick back? That’s literally the job.
Book a diagnosticLoan inputs
Fixed-rate, fully amortizing P&I. Taxes, insurance, and escrow are separate. They belong in their own accounts, not blended into “the mortgage payment.”
Amortization
updates live| Monthly payment (P&I) | — |
|---|---|
| First payment: interest / principal | — |
| Principal paid after 5 years | — |
| Balance after 5 years | — |
| Total interest over full term | — |
| Payoff with extra principal | — |
| Interest saved with extra principal | — |
Show the first 3 years, month by month
| Payment # | Payment | Interest | Principal | Balance |
|---|
Includes any extra principal entered above. This split, interest to expense and principal against the loan, is exactly what should hit your books every month.
Early payments are mostly interest. That’s why the 5-year numbers matter more than the 30-year ones for most investors: they show your real equity build over a typical hold.
In clean books every payment splits three ways: interest to expense, principal to the loan, escrow to its own account. One lump to “Mortgage Expense” is how equity hides.
Book a diagnosticTimeline inputs
Vendor & draw float = days other people’s money carries the project before yours goes out: vendor payment terms plus the lag between paying for work and getting the draw reimbursed. More float, shorter cycle.
Capital lock-up
updates live| Days of capital committed (reno + sale) | — |
|---|---|
| Less: vendor & draw float | — |
| Cash conversion cycle | — |
| In months | — |
| Max deal cycles per year (same capital) | — |
Every day of renovation slip or extra days on market extends the cycle 1-for-1, and the cycle is what caps how many deals your capital can do per year. That variance is an operations number your books should surface weekly.
Is your current bookkeeping setup tracking this variance in real-time? Book a strategy call with GSD to build the system.
Book a strategy callProperty inputs
Holding cost = everything you pay whether units are rented or not: debt service, property taxes, insurance, utilities on vacants.
Monthly burn timeline
updates live| Burn with both units offline | — |
|---|---|
| Burn after unit 1 is leased | — |
| Net after both units online | — |
| Property stops bleeding in | — |
| Cash consumed getting there | — |
First 12 months. Red = negative month, green = cash-flow positive. The month-by-month figures are in the table above.
Every week unit 2’s turn slips, the burn phase stretches and the cash-consumed number grows. That’s why turn timelines belong next to the budget, not in a text thread with your GC.
Staggered flips require splitting site-wide CapEx from unit-specific turns. If your books can’t do this, let’s talk.
Let’s talkDeal inputs
Loan needed = purchase + reno − your down payment. Lenders test that loan two ways: against total cost (LTC) and against ARV (LTV). Both must pass.
Lending ratio check
updates live| Total project cost | — |
|---|---|
| Loan needed | — |
| Loan-to-cost (LTC) | — |
| Loan-to-value (LTV vs ARV) | — |
| Verdict | — |
| Extra down payment to qualify | — |
Safety zones vary by lender: many go to 90% LTC or 75% LTV for experienced borrowers. Whichever ratio binds first sets your maximum loan. These are screening numbers, not a term sheet.
Clean books get faster funding. Ensure your proformas and draw schedules are audit-ready with GSD.
Book a diagnosticCalculator questions, answered
What is the 70% rule in house flipping?
A quick screen for maximum purchase price: pay no more than 70% of the after-repair value (ARV) minus rehab costs. On a $425,000 ARV with $80,000 of rehab, the max allowable offer is $217,500. It approximates profit after financing, holding, and selling costs. Run the full numbers before you write the offer.
How is cash-on-cash return calculated?
Annual pre-tax cash flow divided by total cash invested (down payment plus closing and setup costs). It measures the return on the money you actually put in, not the property price, which is why leverage changes it so dramatically.
What counts as NOI on a rental?
Net operating income = rental income minus operating expenses: vacancy, management, repairs, taxes, insurance, HOA. It excludes mortgage payments and capital expenditure reserves. NOI drives cap rate and DSCR. The two numbers appraisers and lenders quote.
What DSCR do lenders require?
Most DSCR lenders want 1.20–1.25: your property’s NOI must cover the proposed debt service by 20–25%. Below 1.0 the property doesn’t cover its own payment. Higher DSCR generally unlocks better pricing and higher leverage.
What is the cash conversion cycle on a flip?
The number of days your capital is locked in a project: renovation days plus days on market and escrow, minus the float your vendors and lender draws give you. A 120-day cycle means the same capital can only do ~3 deals a year; cut 30 days and you’ve added a deal without adding a dollar.
What LTC and LTV do private and hard money lenders allow?
Most private money lenders cap loans around 85–90% of total project cost (LTC) and 70–75% of after-repair value (LTV). Both tests must pass; whichever is lower sets your maximum loan. Stronger ratios and clean project books typically get faster approvals and better pricing.
How does loan amortization work on a rental mortgage?
Each fixed payment splits between interest and principal. Early on the split is mostly interest; the principal share grows every month as the balance falls. Extra principal payments shorten the payoff and cut total interest. In clean books the split is recorded monthly: interest to expense, principal against the loan balance, escrow to its own account.
Are these calculators financial advice?
No. They’re educational estimates using standard industry formulas and your inputs. Verify every deal with your own numbers, your lender, and your CPA. GSD Accountants is not a CPA firm and does not provide investment or lending advice.
Like these numbers? Your books should produce them automatically.
Per-property P&L, true flip profit, DSCR-ready financials. Every month, without a spreadsheet. Prices published.
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