Here is the formula for estimating an interior paint job. (Hours it takes to do the job x Labor Rate per hour) + Cost of materials + overhead + profit = paint estimate price.
Is that all you need? No? Why not? That's pretty simple.
There really are only a few things to add up and you have your paint job estimate. So maybe you are looking for more. You need to have certain things answered before you are ready to produce an estimate.
OK, then maybe we can produce formulas for each item.
What is your Labor Rate?
Your labor rate cost is the average hourly rate of the people that work for you + taxes + Workers Compensation (because you pay Workers Comp on the hours worked). Multiply times the hours that it takes for the job to be completed. This gives you your labor cost. If you still paint your pay goes here.
What is your Cost of materials?
On a paint job, materials are paint, and other various expendable items that are bought just for this job, as opposed to overhead items such as a truck, ladders, or drops, stuff that lasts for more than this job.
What is your Overhead?
Things like a truck, ladders, or drops, stuff that lasts for more than this job. Other things like liability insurance, telephone, office supplies, generally items that are bought throughout the year that are not able to be charged only to this job. If you don't paint anymore your pay goes here.
What is your Profit?
Your profit is the amount of projected sales for the year. So if you usually do 0,000 per year, and you want the company to make 10% profit then the profit for the year is 0,000 x .10 = ,000. To arrive at the profit for the job, you can divide ,000 by the hours worked per year, and then multiply that by the hours of this job to get the profit to add to this job.
In conclusion, once a year is all you have to do to arrive at your particular selling price, and then every estimate. This is the real way to formulate your hourly rate or your "going rate". If this is too much work then ask the clerk at the paint store what to charge or just guess.
I am just kidding about that that last line.