Flip a House 70 percent rule: Step-by-Step Analysis

The Flip a House 70 percent rule is a real estate investing guideline used to estimate how much an investor may be able to pay for a property before renovation. It uses the home’s projected after-repair value, commonly called ARV, and subtracts the expected cost of repairs.

The basic formula is:

Maximum purchase price = ARV × 0.70 − estimated repairs

The 70 percent factor is intended to leave room for costs beyond the purchase and renovation. However, it is not a guaranteed profit formula. Financing terms, market conditions, selling expenses, project duration, and repair complexity can make the same percentage conservative in one situation and aggressive in another.

A practical analysis starts with two estimates:

• What the property may sell for after improvements.
• What the renovation will cost, including a realistic contingency.

The rule works best as an early filter. It can help identify properties that deserve deeper research, but it should not replace comparable sales, contractor estimates, financing calculations, or a projected net-profit statement.

The calculation is simple, but the estimates behind it require care. Consider a property expected to reach an ARV of $220,000 after renovation, with repairs estimated at $40,000.

Under the rule, $114,000 is the maximum purchase price for the initial screen. If the seller expects more, the deal may still work, but the investor needs a more detailed model that explains why.

A useful ARV estimate should be based on completed sales and realistic market positioning. A property that looks attractive at $220,000 ARV may become a weak project if comparable homes support only $205,000.

For repair costs, list each major category separately. This makes it easier to see which assumptions are uncertain.

The standard formula uses ARV and repairs, but actual flipping expenses can extend well beyond those two inputs. Selling costs may include an agent commission, title charges, seller concessions, transfer fees, and other closing expenses. Holding costs can include taxes, insurance, utilities, maintenance, lawn care, snow removal, and property security.

Financing also varies widely. A cash purchase, bank loan, private loan, and hard-money arrangement can produce very different carrying costs. The longer the renovation and resale take, the more those expenses may affect the final result.

The 70 percent factor may cover some of these costs in broad terms, but it does not know your local prices, financing structure, renovation speed, or selling strategy. An investor with low financing and selling expenses may have more flexibility than an investor facing expensive debt and a slow market.

Project duration deserves special attention. A renovation planned for two months may take six months if permits are delayed, contractors become unavailable, materials arrive late, or hidden defects appear. A longer timeline increases interest and holding expenses while also exposing the project to market changes.

A deal can pass the 70 percent screen and still produce an unattractive return. For example, a low-priced property may appear profitable on paper but leave only a modest dollar gain after financing, holding, and selling costs. The investor is still accepting project risk and spending time managing the renovation.

After the initial screen, replace the general rule with a detailed estimate. Start with the expected sale price and subtract every known project expense. Then add a contingency reserve and the profit target required to justify the work.

A detailed model is more useful than a fixed percentage because it reflects the actual property and the investor’s situation. Include a contingency even when the inspection appears favorable. Renovation budgets often change after walls are opened, systems are tested, or municipal requirements are reviewed.

Use conservative assumptions in three areas:

• ARV: Base the resale estimate on comparable completed sales, not the highest available listing.
• Repairs: Assume some costs will be higher than the first contractor estimate.
• Timeline: Model a slower completion and sale period instead of assuming everything happens quickly.

The 70 percent rule explanation and formula provides a useful reference for the basic calculation, but the final decision should come from your own property-specific analysis.

A custom buying rule can also be useful after reviewing several completed projects. Some investors may discover that a different percentage better reflects their market, financing, average project duration, and selling expenses. Even then, a personal percentage should remain a screening tool rather than a substitute for line-by-line underwriting.

The 70 percent approach remains useful because it is fast, easy to remember, and helpful for screening distressed properties. Its weakness is that two of its most important inputs—ARV and repairs—are estimates. The rule also compresses many other expenses into one broad percentage.

Use it as the first gate in your process:

1. Estimate a conservative ARV.
2. Create a realistic repair budget.
3. Apply the 70 percent calculation.
4. Add financing, holding, selling, and contingency costs.
5. Compare the remaining profit with the project’s time and risk.
6. Make an offer only when the assumptions are supported.

The strongest use of the rule is not deciding that every property below the formula is good or every property above it is bad. Instead, use it to prioritize opportunities, expose weak assumptions, and decide which properties deserve deeper analysis.