How is yield calculated?

When people talk about their gram per watt ratio are they talk about gram per kW hour or simply gram per watt of equiptment?

My first CFL grow yielded me 5.4 oz which is roughly 150 grams running 388w. .4g/w (150/388 ) Is this correct? It doesn't factor in length of veg/flower period...

My grow was over in 8 weeks from seed to harvest running 388w 11 hrs a day for 56 days. 56*11*.388 = 240 kW hours which would make my yield ratio .625 g/kWh

So which of these is correct? And more importantly which one is commonly referenced?

I feel like this could make a HUGE difference when people report g/w ratios.

Say i yield a pound per light with a 5 kW grow where I veg for 12 weeks and flower for 8 weeks.

12weeks*7days a week*18hrs a day*5kW = 7560 kWh for veg (i understand that most people wouldn't veg with all 5kW but this is hypothetical to prove a point)

8weeks*7 days a week*12 hrs a day*5kW = 3360 kWh

Total of 10,920 kWh for grow.

Yielded 2270 grams (lb per light)

Thats .207 g/kWh compared to .454 g/w (2270/5000w)

Thats a HUGE difference.

And if people are really stating that they get a g/kWh they must be magical. That would mean getting around 21 pounds off 5kW according to the scenario above. I'm sure thats possible with a 12 week veg but still has to be much more difficult than so many claim.

Everyone is always throwing out how many g/w they achieve. How are you all calculating it?

I simply go by my total watts of light and my total dry yield in grams

my last harvest was 47.2 grams using 97 watts of light

I believe this is how most growers calculate it

^Agreed. It's grams per watt of light, not kilowatt hours. So, at .45 grams per watt, that's not too bad at all.

Do people not see a HUGE problem with this? Stating g/w means absolutely nothing because you arn't mentioning how many total watts are used. Just how many watts are used at a time.

damn, math skills would be useful right now.

Gastanker said:

Do people not see a HUGE problem with this? Stating g/w means absolutely nothing because you arn't mentioning how many total watts are used. Just how many watts are used at a time.

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In the end it means nothing at all, but the idea is to gauge experience as a grower, with the end goal being 1 gram per watt. It's a way to see improvement in your growing skills. Problem is most want bragging rights and that is not what it is about either

the more you learn and understand about how everything works the more yields you get in the end it's not about the watts at all (lights being only one part of the equation) but it is still how it's done, no reason to change something that doesn't truely mean anything

i have 6 1000w hps for my flowering room and 2 600 w mh lights for my vegging room my strains that are gonna be in my room is afhgan kush, trainwreck ,lsd , blueberry ,blue mystic, the church, super silver haze, the chronic, cheesel, la confidential, himalaya gold, strawberry haze. . im gonna let them grow to be 2 to 3 ft when i strat to let them flower i have a 7.5 ft x15 and a 8 ft in height ceiling i want to get 20 lbs from my plant its gonna be 40 plants in the room. is it possible that i can get that each time at harvest all dried bud weight . this would be my 3rd grow i just brought all the lights and stuff im using soil also. after this first one start i want to harvest every 2 months want to be pulling at the minimum 15 lbs if anybody can help me i would really appreciate it

jolanan said:

i have 6 1000w hps for my flowering room and 2 600 w mh lights for my vegging room my strains that are gonna be in my room is afhgan kush, trainwreck ,lsd , blueberry ,blue mystic, the church, super silver haze, the chronic, cheesel, la confidential, himalaya gold, strawberry haze. . im gonna let them grow to be 2 to 3 ft when i strat to let them flower i have a 7.5 ft x15 and a 8 ft in height ceiling i want to get 20 lbs from my plant its gonna be 40 plants in the room. is it possible that i can get that each time at harvest all dried bud weight . this would be my 3rd grow i just brought all the lights and stuff im using soil also. after this first one start i want to harvest every 2 months want to be pulling at the minimum 15 lbs if anybody can help me i would really appreciate it

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Picture is worth a thousand words

riddleme said:

In the end it means nothing at all, but the idea is to gauge experience as a grower, with the end goal being 1 gram per watt. It's a way to see improvement in your growing skills. Problem is most want bragging rights and that is not what it is about either

the more you learn and understand about how everything works the more yields you get in the end it's not about the watts at all (lights being only one part of the equation) but it is still how it's done, no reason to change something that doesn't truely mean anything

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Like you say g/w means NOTHING however grams per kW hour does mean something. It's an actual quantifiable way of calculating how much everygy you spent to produce a certain result. I'm just confused as to why people dont go through the trouble of calculating it out.

If I dont veg at all and flower for 2 months and get 1000g from my light I get 1g/w. If i veg for 6 months and then get 2000g from my 1000w light then I get 2g/w... But my first grow would yield 1.4 g/kWh whereas my second grow I only yield .5 g/kwH

Thats to say my 1g/w grow was three hundred percent as profitable as my 2g/w grow. Does that make any sense?

Gastanker said:

Like you say g/w means NOTHING however grams per kW hour does mean something. It's an actual quantifiable way of calculating how much everygy you spent to produce a certain result. I'm just confused as to why people dont go through the trouble of calculating it out.

If I dont veg at all and flower for 2 months and get 1000g from my light I get 1g/w. If i veg for 6 months and then get 2000g from my 1000w light then I get 2g/w... But my first grow would yield 1.4 g/kWh whereas my second grow I only yield .5 g/kwH

Thats to say my 1g/w grow was three hundred percent as profitable as my 2g/w grow. Does that make any sense?

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What your saying makes total sense but is more of cost of yield calculation rather than a bar to reach for (if that makes sense)

My friend Ed posted an excel spreadsheet that calculates TOTAL cost to grow (even includes labor)

https://www.rollitup.org/general-marijuana-growing/313524-there-app.html

works great!

Grabbed that app a couple days ago. Great spreadsheet. Small mistake on the power usage page however, a few lines down .11/kWh is static versus reading from the input field. Awesoem spreadsheet once thats fixed though.

But what i'm talking about is for comparisons purposes. People should compare their grow skills based on g/kWh versus g/w of equiptment. Because as you see g/w is not comparable at all. It can only be used as a reference on a personal level when comparing grows of exact equal time using the same exact equiptment.

Thank you for responding by the way. I really appreciate the input.

Gas,

Thanks for pointing that out. When I originally started designing the spreadsheet it was just for my own personal use, so I had the formula for all the cells set up for my own home rate. When I adjusted it to be usable for anyone i changed the formulas in the first couple of cells, but I guess i forgot to copy them down into the rest. I'll correct the master sheet and pass it on to riddle so he can do all the formatting stuff thats needed to get it to post properly (I'm just an accountant who's good with excel and access, he's the one that actually knows computers).

don't mean to sound like a richard, but what difference does it make at all in the grand scheme, lol??? other than knowing the numbers, how is that knowledge going to aid in growing??? you grow how you know, and yield based on that. i don't think mathematics figure into the equation of growing/yield.... imo

Silky Shagsalot said:

don't mean to sound like a richard, but what difference does it make at all in the grand scheme, lol??? other than knowing the numbers, how is that knowledge going to aid in growing??? you grow how you know, and yield based on that. i don't think mathematics figure into the equation of growing/yield.... imo

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Being able to crunch numbers has no direct effect on how your plants perform. However when you are having people comparing methods of growing you generally need reference points - when it comes to marijuana that is generally in the form of profitability.

Unfortunately when you are comparing the talents of large scale growers to small scale growers you cant simply use overall yield as the large scale grower will of course always yield more. So you must compare yield to something else. You can compare yield to the time it took to acquire it. Or you could compare yield to how much equipment you are running. The best way however would be to compare both the equipment you are running to how long you run it. And of course this would be comparing based on kWh to yield versus just the time it took or just the amount of equipment you ran compared to yield.

EdGreyfox said:

Gas,

Thanks for pointing that out. When I originally started designing the spreadsheet it was just for my own personal use, so I had the formula for all the cells set up for my own home rate. When I adjusted it to be usable for anyone i changed the formulas in the first couple of cells, but I guess i forgot to copy them down into the rest. I'll correct the master sheet and pass it on to riddle so he can do all the formatting stuff thats needed to get it to post properly (I'm just an accountant who's good with excel and access, he's the one that actually knows computers).

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Np! Thanks for getting that sheet all done up! Very helpful.

way too many variable to calculate yield. there's the strain, the experience, the equipment, environment, etc. can't be done. after you grow something out once, then you can use that as number to figure, but this will change with each strain...

what's this business with grams per meter squared? on my satori pack it has a picture of a scale (which i assume represents yeild) and it says 400-450 gr/m2. (i know the 2 is supposed to be all little and on top but that's how it says it on the pack.) anyway, i assume this implies "optimum light conditions", but does not mention veg time, light type or watts. so if i veg for 40 days under cfl/t5, then swap to flower under a 400w hps, should i expect the 400 grams if theres say 4 plants that make it? I've seem the grams per meter squared thing but never understood how it could be accurate with all the variables involved.