Every guru will offer a different formula, but one that is commonly used is: 70% of the ARV - Repairs = TARGET PRICETo break that down, that means once you calculate the ARV (After Repair Value) that a property would sell on the market for after your flip is complete, you want to multiply that amount by 70% and then subtract the total cost of your projected repairs.

I multiply that by 1.5 and get a total of $4,012.50 so I round it down to $4,000.

Find an average of how many times each unit might do laundry in a week and then calculate that on a monthly basis and then multiply by the amount of units. 4 Units x 2 Loads/Week x 4 Weeks in a Month = 32 Loads in each a washer & dryerIf you charge $1.00 for each the washer and dryer, then that would be $32 (washer) + $32 (dryer) for a total of $64 in income per month.

Take your current value of your home and multiply it by 80%. 

Ive watched some videos on this, but none of them are in Florida market or new (inflation). If you are quickly analyzing a deal, what numbers do you use for a only cosmetic, cosmetic with some big stuff like roof, and...

Even in those instances using your equity in conjunction with other resources likely only multiplies your efforts. 

Think about all the potential hazards that someone can sue for damages, then multiply that by 2 for all the unforeseen risk hazards.

Supposing you increase the rents on a 4-plex by $40 per year and the Gross Multiplier for similar properties is 15.

Generally, with the exception of pure luck, purchasing no less than a 4-unit property will out-produce a single-family for profit every time because when you increase the rents for a 4-unit property every year by only $40 per unit you automatically increase the value of the property in accordance with the 'Rule of Thumb Gross Multiplier' by $28,800 every year as in this math $40 x 4 x 12 x 15 = $28,800 increase value every year and in 10 years you profit $288,000 plus all your regular cashflow and your total profit could possibly exceed $320,000 to $340,000.I always see 4-unit properties for about the same price as a single-family home. 

The valuation is calculated by the rent roll, meaning how much rent per year are you getting, and then a multiplier is applied to calculate the overall value.