Fix and Flip Calculator for Detroit Deals
Estimate what a Detroit flip really costs and earns: purchase, rehab, holding months, financing, and selling costs. See your max offer under the 70% rule, then compare it with a flip we ran start to finish.
Talk through your dealRun your numbers.
Enter the purchase price, rehab budget, after-repair value, closing and agent costs, holding months, and your loan terms. Leave the loan at zero for an all-cash deal.
Stansbury, run through the math.
19xxx Stansbury (48215) was bought for $35,000, renovated for $52,237, and sold for $134,000 with a 6% agent commission and 2% in closing costs.
| Purchase price | $35,000 |
|---|---|
| Rehab | $52,237 |
| Total cost basis | $87,237 |
| Sale price (ARV) | $134,000 |
| Agent commission (6%) | −$8,040 |
| Closing costs (2%) | −$2,680 |
| Net proceeds | $123,280 |
| Profit before holding costs, financing, and fees | $36,043 |
| Return on cost | 41.3% |
| Max offer under the 70% rule | $41,563 |
The purchase came in $6,563 under the 70% rule's max offer, which left room for holding costs and the split between investor and operator. Enter your own holding months, interest rate, and points in the calculator to see how much of that $36,043 survives. The Stansbury case study shows how the deal was structured and what the investor took home.
What the numbers are telling you.
The 70% rule
Max offer = ARV × 70% − rehab. If your purchase price is above it, the deal needs a reason to work: a cheaper rehab, a faster sale, or a lower return you have decided to accept. Treat the rule as a filter, not a verdict.
ARV
Every number downstream depends on the sale price. Use renovated sales from the same neighborhood in the last six months. In Detroit, values can change block by block, and thin comps mean buyers' appraisals can come in under contract. Run the calculator again at 90% of your ARV and see if you still like the deal.
Holding costs and time
Every month adds interest, taxes, insurance, and utilities. Annualized ROI falls fast when a four-month plan turns into nine months. Count from purchase closing to sale closing.
Detroit-specific risks
- Permits and city inspections. Electrical, plumbing, mechanical, and structural work need permits, and inspection scheduling can add weeks. Build that into your holding months.
- Scope growth. Older Detroit housing hides surprises: sewer lines, foundations, knob-and-tube wiring, and roofs. Keep a 10% to 15% contingency on the rehab.
- Vacancy risk. Empty houses attract theft of copper, furnaces, and water heaters. Budget for security and frequent site visits.
- Days on market. Some neighborhoods sell in weeks. Others take months, and buyers often rely on FHA or other financing that adds appraisal and repair conditions.
- Plan B. If the house doesn't sell, could it rent? Run it through the DSCR loan calculator before you buy, so holding it is a real option and not a scramble.
Detroit flips we ran start to finish.
Sourcing, renovation, and sale, with the numbers and the before and after photos.
19xxx Stansbury
Bought for $35,000, renovated for $52,237, sold for $134,000. The worked example on this page.
Read the case study Flip · 4823814xxx Prairie
A full renovation on the west side that sold for $95,000. Before and after photos.
Read the case study Flip · 482152xx Marborough
An east-side renovation listed at $229,900. Before and after photos.
Read the case studyFlipping houses in Detroit.
What is the 70% rule for flipping houses?
The 70% rule says your maximum offer should be about 70% of the after-repair value (ARV) minus the renovation budget. On a house that will sell for $134,000 after a $52,237 rehab, that is $134,000 × 0.70 − $52,237 = $41,563. The 30% gap is meant to cover selling costs, holding costs, financing, and profit.
Does the 70% rule work in Detroit?
As a first filter, yes. On low-priced Detroit houses the fixed costs (permits, inspections, utilities, insurance) take a bigger share of the deal, so the 30% cushion gets thin fast. Run the full numbers, including holding months, before you make an offer.
How do I estimate ARV for a Detroit house?
Use renovated sales within a few blocks from the last six months, matched on size, bedrooms, and condition. Detroit values can change street by street, so a sale across a main road may not count. When comps are thin, expect the buyer’s appraiser to come in lower than you hope.
What holding costs should I include?
Loan interest, property taxes, insurance (vacant-property coverage costs more), utilities, lawn and snow, and security. Count every month from closing on the purchase to closing on the sale, not just the renovation months.
What are the biggest risks on a Detroit flip?
Scope that grows after demo, permit and city inspection delays, theft or vandalism while the house sits vacant, appraisals that come in under contract, and long days on market in some neighborhoods. Have a Plan B, such as renting the house, before you buy.
Can Great Lakes PMG lend on my flip?
No. We are a licensed real estate brokerage and property manager, not a lender. We help you source the house, scope and manage the renovation, list and sell it, or lease it if renting makes more sense.
Not financial, lending, legal, or tax advice. The calculator and the ranges on this page are estimates for planning. Lenders set their own terms, and every property is different. Confirm numbers with your lender, CPA, and attorney before you buy. Past results in our case studies don't guarantee future returns.
Have a flip you're weighing?
Book a free call. Bring the address and your numbers. We'll look at the comps, the rehab scope, and the timeline, and tell you where we think the risk is.