The REI Vault Pro MAO Calculator: How to Calculate Maximum Allowable Offer on Any Real Estate Deal

Every real estate investor eventually faces the same moment: a motivated seller, a property with potential, and the temptation to stretch the offer to win the deal. The investors who build durable, profitable businesses are the ones who resist that temptation — not through willpower, but through discipline. They know their maximum number before negotiations begin, and they do not exceed it regardless of how much they want the deal.

The Maximum Allowable Offer is that number. Calculated correctly before every offer, it is the ceiling that protects your profit on every transaction. The REI Vault Pro MAO Calculator builds it from first principles — ARV, repair costs, every category of carrying expense, and your required profit margin — so the number is defensible, not arbitrary.

What Maximum Allowable Offer Actually Is

MAO is the highest price you can pay for a property while still achieving your minimum required profit at your target exit. It is calculated backward from the exit — starting with what the property will be worth after renovation (ARV) and subtracting every cost between purchase and sale.

The formula the MAO Calculator uses:

MAO = (ARV × Target Margin %) − Repair Costs − Holding Costs − Closing Costs − Desired Profit

Each of these inputs represents a real cost category that must be funded between your purchase date and your sale date. Omit any of them and your MAO is inflated — which means your minimum required profit is at risk before you break ground.

Breaking Down Every Input

After Repair Value (ARV)

ARV is the post-renovation market value of the property. This is not what you hope it will sell for. It is what the comps support, calculated using the ARV Calculator from comparable sales within half a mile, sold in renovated condition within the last 6 months.

ARV is the most consequential input in the MAO calculation. A $20,000 ARV overestimate translates directly to a $20,000 MAO overestimate and a $20,000 reduction in actual profit at exit. Use the conservative end of your comp range, not the ceiling.

Target Margin Percentage

The standard margin used in the 70% rule is 70% of ARV — meaning the maximum you should pay, before subtracting costs and profit, is 70% of what the property will be worth renovated. The 30% buffer covers all the expenses between acquisition and sale: repairs, holding costs, financing, closing costs on both sides, and profit.

The MAO Calculator lets you adjust this percentage for your market and strategy. In fast-moving markets with thin inventory and strong buyer demand, some investors work at 72–75%. In softer markets, riskier deals, or deals with significant execution complexity, 65% is more appropriate. The standard 70% is the right starting point for most deals.

Estimated Repair Costs

Your full renovation budget including contingency — not a round number estimate but a scope-based calculation. Use the Rehab Cost Estimator to build a line-item budget first, then plug the total (including contingency) into the MAO Calculator.

Under-estimated repairs are the most common reason MAO calculations fail in practice. Every dollar of repair cost overrun comes out of the profit column.

Holding Costs

The total cost of owning the property from purchase to sale: monthly interest on your bridge or hard money loan, property taxes, insurance, utilities, and HOA fees — multiplied by your projected hold period in months.

Use the Bridge Loan Calculator to model your financing cost, then add the non-financing holding costs for your expected timeline. For a 6-month flip at $1,500/month in total holding costs (interest, taxes, insurance, utilities), budget $9,000 in this input.

Closing Costs

Both sides: the buy-side closing costs when you acquire (title, escrow, lender fees, origination points) and the sell-side closing costs when you exit (agent commission, title, transfer taxes, seller concessions). Use the Closing Cost Calculator for accurate line-item estimates on both sides.

Sell-side closing costs alone often run 7–9% of the sale price. On a $250,000 ARV, that is $17,500–$22,500. This is the single most commonly underestimated line item in fix-and-flip analysis.

Desired Profit

Your minimum acceptable net profit on the deal. This is the floor — the amount you require to execute the transaction. Budget at minimum $20,000–$30,000 net profit on a standard single-family flip. Less than that and the risk-adjusted return does not justify the execution risk.

Entering your desired profit as a hard number (not a percentage) ensures the MAO reflects what you actually need to earn, not a formula abstraction.

The 70% Rule MAO: The Quick Screen

The calculator also returns the 70% Rule MAO: simply ARV × 0.70 minus repair costs. This simplified version omits holding costs, closing costs, and desired profit as separate line items — folding them into the 30% margin buffer instead.

The 70% Rule MAO is a fast screen. If the asking price is above the 70% Rule MAO, the deal is unlikely to work without a significant price reduction or an unusually low repair cost. Use it to eliminate properties quickly before running the full MAO calculation.

For offers you are actually submitting, use the full MAO calculation with every cost category explicitly modeled.

MAO as % of ARV

The calculator outputs your MAO as a percentage of ARV — for example, 64.5%. This ratio tells you how much room the deal has relative to market value.

An MAO at 65–75% of ARV is within the normal range for most residential fix-and-flip deals. An MAO at 80%+ of ARV means the deal's margin is thin and any cost overrun puts you at risk. An MAO below 60% means the deal has exceptional spread — often found in distressed properties in strong markets, or properties requiring minimal renovation.

The Most Important Discipline in Investing: Knowing When to Walk

The MAO is only useful if you honor it. Every experienced investor has stories of deals they stretched beyond their MAO to win — and most of those stories end the same way.

When a seller will not meet your MAO, the appropriate response is not to adjust the MAO — it is to walk away. The deal does not work at that price. Another deal will come. The investors who stay disciplined on their numbers across hundreds of transactions build portfolios with consistent, predictable returns. The investors who stretch accumulate a portfolio of marginal properties that require constant subsidization.

Calculate your MAO before every offer. Submit at or below it. Walk away when the price does not work.

Open the MAO Calculator and run your next acquisition through the complete formula. Available to Core and Pro members. Start your 7-day free trial today.