Wow,
I would have thought more people would have been interested in keep tracking of what it costs them to grow their stuff. After all, thats what you base your sale prices on, or it should be. It's not like this sheet takes a lot of time to fill out or is tough to use either. I've got figures plugged into a few of the white cells to serve as examples, so just replace them with your own figures or zero them out.
Anway, bit more about how to use the sheet. The first page is basically your totals page, and the only things you need to plug in there are the costs for things like rent, security, etc, that don't require any sort of serious calculations to figure out. Be aware that the sheet is set up to automatically figure the cost for the full three month grow period based upon whats entered into the monthly costs column, so one time expenses need to be divided by 3 before entering into the monthly costs column. Licenses and fees should also be divided by the number of months they cover (i.e. a 12 month license that cost $24 would be 24/12=$2 per month) and that figure entered into the monthly cost column.
The light cost worksheet is designed to let you calculate your electrical costs in advance based upon anticipated usage of various lights. The only real variable here is the number of days in the grow, so if you're on a solid vegging schedule that figure should always be dead accurate. You can get the figure you need to plug into the Kilowatts cost per hour from your public service bill. If it doesn't break it down for you, just figure out the total kilowatt hours used and divide by the charge for electrical usage to get the kilowatt rate per hour.
The nutrients cost sheet is pretty self explanatory. Just plug in the price and the percentage of the package used. You can include insecticide, soil, nutrient supplements like mollasses-pretty much anything thats directly going into growing and/or keeping the plant healthy.
The equipment costs worksheet- This is actually a very basic fixed assets depreciation schedule, and can serve multiple functions. Besides feeding in the equipment costs for each grow it will also serve as the basis for the monthly depreciation adjustments that need to be done to your fixed assets (equipment) ledgers for accounting and tax purposes, and can serve as your primary fixed assets list for your accountants/auditors. Because most of the assets involved fall into the "fixtures" category I've set this sheet up to use a 3 year straight line depreciation schedule for everything. The formulas WILL need to be adjusted if this is used to record any item that is legally required to use a different depreciation time period (1 or 5 years are fairly common) or a different depreciation method.
The days in grow figure is the total number of days of the grow, not the number of days any particular item was used.
I've already talked a bit about the labor cost worksheet, but I wanted to point out the time spent per plant calculation. I'm still a noob when it comes to growing, but even i can see that you rarely need to spend more then a minute or two on any one plant during the course of the day. I've had many people tell me how much time they spend on their plants, so it got me wondering how much of that time was really necessary. Well, this calculation is the beginning of my search for an answer. By figuring out how much time each person spent actually working on the plants during the grow you become better able to control your labor costs, so when your idiot nephew Jimmy trys to tell you that he spent 2 hours watering the plants yesterday you can look at the chart and tell him that it should only take about 10 minutes on average. I'm still working on expanding that portion of the sheet, and plan to add a daily time spent per plant calculation. Something else I've considered is doing a sheet so that you can tie each plant and each yield to a specific person assigned to tend it, which would allow you to see not only how much time/money each person was spending per plant, but also how that spending effected (or didnt effect) those plants yields. If that's of interest let me know and I'll see what i can do about adding it.
Final note- I still need to add a line for costs that aren't big enough to warrant depreciation, and that's full expense will be put on the books at the time of purchase. This category would be for things like pots, mylar film, cheap fans (under $100), etc.