How to calculate yield

A question I get a lot is:

How many seeds to get 1000 grams or how much will one plant yield indoors?

Its not really about the amount of seeds but more the amount of watts you are using and the size of your plants. 600 watt HPS will yield (atleast) 200 to 500 grams.


I,m just switching to a 350 Watt LED. What do you guys think of these?


LEDs are great if you get a good one. The problem is it is very hard to know what to look for and there are tons of cheap knock offs out there.


How can you guess what your yield will be if you’re growing outside? Is it just by the size of the plant? And growing techniques, strain, etc.?

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I must be doing something wrong. I’m using a 1,000 watts and I have a hard time getting 45 grams per plant. Any help is appreciated

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How many grams you harvest has a lot to do with how efficiently you use your space and how well the lights is being used for the space.

How are you growing?

We could use more info. What are the parameters in your grow?

Let’s get you started with a ILGM support ticket that Latewood had first developed. It’s is a great checklist of things in your plant’s environment that might help give us an idea of what could be going wrong.

Answer all the relevant questions the best you can, if you do not know, or do not use something, just say so or put ‘NA’.

ILGM Support Ticket:

What is the strain and type(strain name, unknown bag seed, regular seeds, feminized seeds, auto-flower, etc)?

Indoor or Outdoor? If outdoor, planted in ground or in a container?

Size of space (max height and area, length/width)?

Soil or Hydro? Type of Medium used? System type?

pH? Of the soil or medium (root zone/reservoir/runoff) and of the water and/or nutrient mix that is fed to the plant?

Type and strength of nutrients used? NPK? EC/TDS/PPM levels?

Temperature? Day vs. night temp or highest and lowest temps? Root zone temps?

Humidity %?

Light system/watts/lumens/FLUX/PAR?

Ventilation system? Size? CFM? CO2? AC, Humidifier, De-humidifier?

Number “weeks/days” from into Season, Vegetative Growth or Bloom/flowering?

Add anything else you feel would help us give you a most informed answer. Feel free to elaborate, but try to be brief and to the point. Short and to the point questions and facts will help us help you :slight_smile:



There are yields estimates for each of our seeds in the seed’s description in the shop.

Something like 300-600 grams approximately per square yard or square meter from a healthy plant or plants, in general, that are effectively using the light available to them – for most strains. Of course this shouldn’t be expected to be so high from certain strains or from most peoples first grows, and probably not at all that high of yields for autoflower strains. And these numbers would likely be on a little higher side when grown outdoors.


When the yield for your seeds are stated, 16oz/1 sq. meter, for example, is that per plant or per 1 sq. meter. I have 3 purple haze in a 22" x 34" tent. About what will the yield be? Thanks

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Although some strains can yeild up to and sometimes more than a pound per plant, that would be a huge plant taking up at least a square meter if not much more area.

Yes, it is per square meter, not per plant. If you have 22 inches by 34 inches of area, that equals 743 square inches, right? That would be about 0.48 square meters, or for the sake of simplicity about a half a square meter, which is what I would’ve guessed by “eyeballing it” knowing a yard is 36 inches and a meter is about 39 inches. And so at a square half meter at 16oz/sq. meter, you’d have a little less than 8 oz.

This is if everything goes right and in the best of circumstances, so most would not likely expect this their first grow, or until experienced with said strain.

Hope this helps.

Happy Growing,



The only way you truly know what you can grow per plant, per meter, per SF’; Is to grow using your methods and techniques. Grow after grow, you will gauge your results; And that is the best answer to your question.

What you should be asking is; 'How do I yield a gram per watt"? This is the measure; And, or, benchmark we all strive to achieve. Happy growing.


What are you growing (strain)?


That’s a lot of information that is cool I didn’t know all


You know that there are “auto’s” that give that much yield - there are about 2 breeder - being new to the site can I give the name of the strains that produce 1000 gr? I don’t want to “spam”


why not…please do.



Heavyweight Seeds - Vast & Fast Seeds - Buddha Seeds do you want names of strains ?


Hey Steve,

You can message me also. It’s private. Just click on my symbol and click message



@garrigan62 hey bro is GPW figured by total watts in a certain area or is it figured by each led, and I know they are at the wall wattages which are the true watts


I got 9 lbs from under (5)-1,000watt HPS Lights…
Grew 84 plants, topped once and grow in the SOG method with very little LST or pruning. After topped and all top colas and side branches evened up in height and very little pruning, I just let them go and was amazed at how easy it was so it depends on many factors to calculate yield.
I have learned more than anything that ph and ppm monitoring and steadiness are the biggest factors between a great grow and just an ok grow. Bc without the ph and ppm being right, it doesn’t matter what nutes used, lights grown under or other environmental conditions since correct ph and ppm is needed for any of those factors to even work. Just keep perfecting your techniques and experiment even within the same grow and keep track of what works and doesn’t work. IMG_0327|666x500
This came off 1 White Rhino plant that wasn’t but 2.5’ tall.


Just harvested a beautiful blue dream. The wet weight is 3329gramx. How much dry can be predicted from that?