The 70% Rule: When It Works & When It Deceives Fix and Flippers

The 70% rule is one of the first formulas a new real estate investor learns. It’s presented as a simple, powerful guardrail to prevent you from overpaying for a fix-and-flip property. For decades, it has served as the industry's go-to shortcut for calculating a rough offer price on the fly.

The problem is, a shortcut that ignores nuance is a direct path to a smaller bank account. While the 70 percent rule provides a decent ballpark estimate in a narrow set of circumstances, relying on it as your primary underwriting method is one of the fastest ways to lose money in modern real estate investing. It's a blunt instrument in a business that demands surgical precision.

This guide breaks down the math behind the rule, explains its fundamental flaws, and walks through three real-world deal scenarios where trusting the 70% rule led to drastically reduced profits and missed opportunities. We will show you why a detailed, bottom-up analysis is the only way to protect your capital and succeed in the competitive world of flipping houses.

What is the 70 percent rule in real estate?

The 70 percent rule is a guideline used by fix-and-flip investors to determine the maximum price they should pay for a distressed property. It states that an investor should pay no more than 70% of the home's After-Repair Value (ARV) minus the total cost of renovations.

How does the 70 percent rule calculate the max allowable offer?

To calculate the max allowable offer (MAO) using this rule, you multiply the property's projected ARV by 70% (or 0.70) and then subtract your estimated repair budget. The underlying assumption is that the remaining 30% of the ARV is a sufficient margin to cover all other expenses—including holding costs, closing costs, financing, and your desired profit.

For example, imagine a property with a solid ARV of $350,000 that needs $45,000 in repairs. The calculation would be:

* ($350,000 ARV x 0.70) - $45,000 Rehab = $200,000 MAO

In this scenario, the rule suggests that if you purchase the property for $200,000, you have a $150,000 gross margin ($350k ARV - $200k Purchase) to cover the $45,000 rehab and all other costs, leaving you with a profit. The 30% slice of ARV ($105,000 in this case) is the bucket of money meant for profit and all non-rehab expenses.

Why does the 70 percent rule fail investors?

The 70 percent rule fails because it falsely assumes that profit and transaction costs are a fixed percentage of a home's final value. In reality, costs like loan interest, insurance, property taxes, and agent commissions do not scale linearly with the ARV, making a fixed 30% margin an unreliable and often misleading metric.

This flaw means the rule can be dangerously inaccurate at both the high and low ends of the market. For lower-priced homes, the 30% margin is often excessively conservative, causing you to submit uncompetitive offers and lose deals. For expensive homes, that same 30% margin is often far too thin to cover the magnified carrying costs and commissions, deceiving you into a deal with a razor-thin or non-existent profit.

What costs does the 30% margin really need to cover?

The 30% margin must cover every single cost outside of the renovation budget, plus your entire profit. These costs are a mix of fixed-dollar amounts, percentages of the purchase price, and percentages of the sales price, which is why a single rule of thumb breaks down.

This bucket of expenses includes:

* Financing Costs: Loan origination points (1-3% of loan amount), interest payments over the holding period (typically 4-9 months), and other lender fees.

* Buying & Selling Costs: Escrow fees, title insurance, and transfer taxes on both the purchase and the sale. Crucially, this includes real estate agent commissions on the final sale (typically 5-6% of the ARV).

* Holding Costs: Property taxes, hazard insurance, and utilities (water, electricity, gas) for the entire duration of the project.

* Your Desired Profit: The net profit you aim to make for your risk and effort, often targeted as 10-15% of the total project cost.

Treating this complex web of costs as a simple 30% of ARV is where the danger lies.

When does the 70 percent rule overestimate your profit? (Deal 1)

The rule frequently overestimates your potential profit on higher-priced properties, leading you to overpay. This happens because percentage-based costs, especially the 6% real estate agent commission on a high ARV, consume a much larger dollar amount from the 30% margin than the rule implicitly accounts for. Longer holding times typical of high-end renovations further erode the margin with mounting interest and tax payments.

How did the 70 percent rule fail a luxury flip in Tampa?

An investor targeted a property in a desirable neighborhood of Tampa, FL, a competitive market. The property needed significant work but had a strong potential ARV of $950,000. The rehab was estimated at a substantial $120,000.

Using the fix and flip 70 rule, the investor calculated their MAO:

($950,000 ARV x 0.70) - $120,000 Rehab = $665,000 - $120,000 = $545,000 MAO

Confident in the formula, the investor purchased the property at $545,000. The 30% margin ($950,000 x 0.30 = $285,000) seemed more than enough to cover costs and yield a six-figure profit. However, the reality of high-end costs told a different story.

The rule suggested a $285,000 gross profit margin to cover all non-rehab costs. The actual non-rehab costs totaled $120,000 ($66.5k + $48k + $5.5k), which should have left a profit of $165,000. But due to a modest rehab overage, the final profit was only $140,000. The rule wasn't just off—it lied about the potential profit by over $100,000. The investor walked away with a profit, but one that was 50% smaller than their initial analysis promised.

When does the 70 percent rule underestimate your max offer? (Deal 2)

The 70 percent rule often forces you to make offers that are too low on more affordable properties, causing you to lose deals you could have won profitably. On lower-priced homes, many costs (like title fees) are fixed or semi-fixed, and the total dollar value of percentage-based costs is smaller. This means the actual costs and a healthy profit margin often consume far less than 30% of the ARV, allowing you to bid higher than the rule suggests.

How a low-cost flip was lost by following the rule.

An investor found a small single-family home in a stable Ohio market that was perfect for a quick, cosmetic flip. The numbers seemed straightforward:

* ARV: $200,000

* Rehab Estimate: $30,000

Following the 70 percent rule, the investor calculated their max allowable offer:

($200,000 ARV x 0.70) - $30,000 Rehab = $140,000 - $30,000 = $110,000 MAO

The investor offered $110,000 and was quickly outbid. The property sold for $119,000. Frustrated, the investor assumed the winner overpaid. But let's analyze the winning bid:

* Purchase Price: $119,000

* Rehab: $30,000

* Selling Costs (7% of $200k): $14,000

* Holding Costs (4 months @ $1.2k/mo): $4,800

* Buying Costs (1% of $119k): $1,190

* Total Project Cost for Winner: $119k + $30k + $14k + $4.8k + $1.19k = $168,990

* Winner's Net Profit: $200,000 ARV - $168,990 Total Cost = $31,010

The winning bidder made over $31,000 in four months—an excellent return. The first investor missed this profitable opportunity because their formula was too rigid. The 70% rule required a $60,000 margin ($200k x 0.30) to cover costs and profit. The actual non-rehab costs were only about $20,000. This left plenty of room for a strong profit even at a higher purchase price. The rule was too conservative and cost the investor a great deal.

How can market conditions make the 70% rule obsolete? (Deal 3)

The 70% rule is completely undermined by market volatility because it's based on a single, static ARV figure. A market that shifts even moderately during your 6-to-9-month project timeline can completely invalidate your initial calculations. In a depreciating market, your profit margin can vanish, while in a rapidly appreciating market, the rule may have caused you to leave significant money on the table.

How a market shift shrunk profit on a Phoenix deal.

In a hot market cycle, an investor bought a property in Phoenix, AZ, intending to perform a moderate renovation. The initial underwriting looked solid:

* Initial ARV: $480,000

* Rehab Estimate: $55,000

* 70% Rule MAO: ($480k x 0.70) - $55k = $336,000 - $55,000 = $281,000

The investor won the deal with an offer of $280,000. The project took seven months, during which interest rates rose and the Phoenix market began to cool. By the time the house was listed, new comps supported a lower ARV.

* New ARV at time of sale: $455,000 (a 5.2% drop)

Let's analyze the financial outcome:

* Purchase Price: $280,000

* Rehab: $55,000

* Selling Costs (7% of $455k): $31,850

* Holding Costs (7 months @ $3k/mo): $21,000

* Buying Costs (1% of $280k): $2,800

* Total Project Cost: $280k + $55k + $31.85k + $21k + $2.8k = $390,650

* Actual Net Profit: $455,000 Sale Price - $390,650 Total Cost = $64,350

The investor's initial analysis, based on the 70% rule's 30% margin ($480k x 0.30 = $144,000), suggested a potential profit well over $100,000. The actual profit was $64,350. The rule's failure to account for market risk meant the investor's profit expectations were off by more than 50%. The deal was still profitable, but the risk was far greater and the reward far smaller than the simple formula suggested.

How should you calculate your max allowable offer instead?

You should calculate your max allowable offer using a detailed, 'bottom-up' method that accounts for every specific cost variable of your project. This approach starts with your desired outcome and works backward to find the only variable you can truly control: your purchase price.

The reliable formula is:

MAO = ARV - Rehab Costs - Holding Costs - Buying/Selling Costs - Financing Costs - Desired Profit

This method forces you to think through each line item. You must accurately estimate your holding time, get real quotes for insurance, look up property tax records, and secure a term sheet from your lender. It replaces a broad-stroke assumption with a detailed, defensible financial model of your project.

What tools can help you accurately calculate your MAO?

While you can build a comprehensive spreadsheet, dedicated software is far more efficient and less prone to formula errors. A professional-grade deal analyzer, like the one we've built at FlipRuns, allows you to input dozens of specific variables—from loan points to utility costs—to generate a precise MAO and a full profit-and-loss projection.

For a quick baseline, you can use a simple digital tool like our free 70% Rule Calculator, but it should only be a starting point. Your final offer must be based on a detailed analysis that reflects the unique economics of your deal and market. Gaining a deep understanding of local cost benchmarks by researching specific locations on a real estate market data platform is a non-negotiable step before deploying capital.

Frequently asked questions

Is the 70% rule good for beginners?

It's a reasonable starting point for beginners to avoid a catastrophic overpayment on their first deal. However, they must understand its limitations from day one and learn to perform a detailed, bottom-up analysis as quickly as possible. Relying on it for more than a few initial deals is a serious handicap.

What about the 75% or 80% rule?

These are simply variations of the same flawed concept, sometimes used by investors in high-cost-of-living areas or extremely competitive markets to justify higher offers. They suffer from the exact same problem: using a fixed percentage to approximate a complex set of variable and fixed costs. An 80% rule might help you win more deals, but it also significantly increases your risk if your cost assumptions are wrong.

Does the 70% rule include financing costs?

The 70% rule is meant to implicitly include financing costs within its 30% margin. However, it does so very imprecisely. The costs of a 10% interest hard money loan are drastically different from a 6% interest private loan or paying cash. This lack of specificity around financing is one of the biggest reasons the rule fails.

Can I use the 70% rule for BRRRR deals?

No, the 70% rule is designed exclusively for the fix-and-flip model and is not appropriate for BRRRR (Buy, Rehab, Rent, Refinance, Repeat). The BRRRR strategy's success is based on the property's ability to support a cash-out refinance that repays the initial capital, which is tied to rental income and lender LTV requirements, not just the ARV. It requires a completely different underwriting model.

How do I get an accurate ARV?

An accurate After-Repair Value (ARV) is the cornerstone of any deal analysis. You find it by pulling comparable sales data ('comps') of recently sold (within 3-6 months) properties that are geographically close (within 0.5 miles) and highly similar in size, age, room count, and level of renovation to your target property's finished state. You must then make specific dollar adjustments for any differences to arrive at a defensible ARV.

The Bottom Line

The 70% rule isn't entirely useless. It can be a helpful mental shortcut to quickly filter out obviously overpriced properties when you're scanning dozens of listings. But it should never be the tool you use to make a final investment decision.

It's a guardrail, not a GPS. Successful real estate investors operate with precision, building a detailed financial model for every single deal. They understand their market, their costs, and their profit requirements, and they use those inputs to calculate a max allowable offer from the bottom up. By abandoning the 70% rule in favor of meticulous analysis, you move from being a speculator to a professional operator—and that is where long-term success in this business is found.