If you’ve ever received a cash offer and thought, “How did they come up with that number?” you’re not alone. Cash offers can feel mysterious, especially when the buyer says they’ll purchase your home as-is and close fast.

Here’s the good news: in most cases, the math is straightforward. Cash buyers are trying to create a predictable outcome. They want to know what the home will be worth, what it will cost to get it there, and what margin is needed to cover risk and profit.

This guide explains the mechanics step by step so you can compare options with confidence, ask better questions, and avoid surprises.

The Big Idea: Cash Offers Start With “What Is the Home Worth?”

Nearly every cash offer begins with an estimate of the home’s current market value, based on nearby comparable sales (often called “comps”). This is true whether the buyer is a local investor, a “we buy houses” company, or a large home buying platform.

A common way to estimate value is a comparative market analysis (CMA), which looks at recent sales of similar homes and adjusts for size, condition, location, and features. Zillow explains that a CMA is built from multiple comparable properties and is used to estimate an accurate value for a home in today’s market: Zillow – What Is a Comparative Market Analysis (CMA)?

For a homeowner, this is the first control point. If the value estimate is off, everything downstream will be off too. That’s why getting multiple opinions often reduces anxiety and helps you feel in charge of the decision.

Step 1: Determine the “After Repair Value” or the As-Is Value

Cash buyers usually base their calculations on one of two value targets:

• As-is value: what the home would sell for today in its current condition.
• After repair value (ARV): what the home could sell for after updates and repairs.

Which one they use depends on the buyer’s business model. A fix-and-flip investor cares about ARV because they plan to renovate and resell. A landlord buyer may care more about as-is value and rental potential. An iBuyer often blends both: current value, market risk, and repair deductions.

Either way, your home’s condition matters. Even Zillow notes that cash buyers may purchase as-is, but they often offer less to account for repairs and other costs they expect after purchase. Zillow – Should I Accept a Cash Offer for My House?

Step 2: Subtract Repairs (And Not Just the Obvious Ones)

Repairs are the most emotional part of the calculation. Homeowners think, “It’s not that bad.” Cash buyers think, “What could go wrong once walls open up?”

Most buyers build in a buffer for unknowns. They’re not just pricing paint and carpet. They’re thinking about the items that derail budgets:

• Roof or HVAC end-of-life
• Plumbing or electrical updates
• Foundation, drainage, or moisture issues
• Permits, code upgrades, and cleanup
• Time delays (which increase holding costs)

This is also where two cash offers can differ a lot. One buyer may have a cheaper contractor. Another may assume higher risk. That difference is exactly why multiple offers create more certainty.

Step 3: Subtract Selling Costs, Holding Costs, and Risk

Cash buyers don’t just subtract repairs. They also subtract the costs of doing business. Even if they plan to resell quickly, there are expenses along the way:

• Closing costs and title fees
• Insurance, taxes, utilities, and maintenance while holding the property
• Financing costs (yes, even “cash” buyers may use lines of credit)
• Agent commissions and seller concessions when they resell
• Market risk if prices soften or the home takes longer to sell

This is the “invisible” part of the math. It can feel like the buyer is discounting your home unfairly. In reality, they’re trying to avoid surprises and protect their margin.

Step 4: Apply the Investor Formula (Commonly the 70% Rule)

Many fix-and-flip investors use a quick rule of thumb to set their maximum offer. The most well-known is the 70% rule:

• Maximum Offer = (ARV × 70%) − Estimated Repairs

The idea is that the 30% “spread” helps cover expenses like selling costs, holding costs, financing, and profit. HomeLight explains the 70% rule and why investors use it as a fast way to avoid overpaying: HomeLight – What Is the 70% Rule in House Flipping?

Important detail: not every cash buyer uses 70%. Some use 65%. Some use 75% in hot markets. Some don’t use a percentage at all and instead price off rental returns or a buy-and-hold model.

Investor vs iBuyer vs “List It”: How the Calculations Differ

One reason homeowners feel confused is that “cash offer” can mean different things. Here’s the simple way to compare:

Local investor or “we buy houses” buyer

• Often ARV-based
• Repairs and risk play a big role
• Usually prioritizes speed and as-is simplicity

iBuyer-style offer

• Typically starts closer to market value
• Then subtracts service fees and repair deductions after inspection
• Can feel predictable at first, then change after the walkthrough

Traditional listing with an agent

• Usually targets full retail price
• But includes prep costs, showings, time, and buyer negotiations
• May involve appraisal and financing risk

The “best” path depends on your priorities: certainty, speed, simplicity, or maximizing price. The key is knowing what you’re trading to get what you want.

A Real-World Example of a Cash Offer Calculation

Let’s say your home could sell for $400,000 after repairs (ARV). A cash buyer estimates $35,000 in repairs. Using a 70% rule approach, the maximum offer might look like this:

• $400,000 × 70% = $280,000
• $280,000 − $35,000 repairs = $245,000 maximum offer

If that number feels low, it helps to remember what’s inside the “spread”: resale costs, holding costs, and risk. A buyer who can renovate cheaper or sell faster might offer more. A buyer who expects bigger issues might offer less.

For you, the homeowner, the win is clarity. Once you understand the math, you can ask the right questions: “What value are you using?” “What repairs are you assuming?” “What’s your inspection process?”

How to Tell If a Cash Offer Is Fair

A fair cash offer doesn’t have to be your highest number on paper. It should feel transparent and predictable. Use this simple checklist:

• Value check: Does their value estimate match recent comps in your neighborhood?
• Repair logic: Can they explain repairs clearly without vague “adjustments”?
• Process clarity: Do you know when the price can change (and why)?
• Timeline control: Can you choose a closing date that fits your life?
• No surprises: Are fees and deductions explained up front?

If you’re getting pressure or unclear answers, that’s a signal. A professional cash buyer should be calm, specific, and easy to understand.