There’s nothing better in life than the day you harvest a crop of home-grown cannabis. The next best thing? Scoring a completely legal free ounce from your next door neighbor.
The only drawback from getting cannabis outside of a dispensary is that it comes with the question “How much THC is in my weed?”
The amount of THC in weed can range anywhere from 0.3% in high CBD strains or reach up to 37% and higher (if the lab tests are to be believed). The percentage of THC in cannabis can vary widely depending on genetics, soil health, and harvest timing.
Why should I find out how much THC is in my weed?
If you’re smoking or vaporizing, it’s not as important to figure out how much THC is in your cannabis. The effects come on and wear off more quickly and you can start with a small puff and wait 10-15 minutes to figure out if you’ll need more.
When making homemade edibles and tinctures with high THC cannabis, it’s important to do the dosage math so you don’t end up experiencing things like extreme munchies, couch lock, dysphoria, cotton mouth, etc…
Cannabis, when taken as food or in tinctures, can be very strong medicine, and even if you have a tolerance, one misstep in dosage math could end in a negative experience.
The goal with dosage math is to get a close approximation of how many milligrams of THC will be in your cannabis recipes so you get more consistent benefits without the negative side effects sometimes associated with high THC cannabis use.
When you do your dosage math and start low and go slow, you’re much less likely to have an unexpected uncomfortable experience with high THC edibles and can reap the benefits that this powerful cannabinoid has to offer.
How much THC is in weed in the US?
When your mom takes a hit off your cannabis and says it’s so much stronger than it used to be, it isn’t just because her tolerance is low. The percentage of THC in cannabis in the United States has risen from 1% in 1972, to 4% in the 1990s, to 17% in 2017.
If you’re in the U.S., you can start by using the average percentage of THC in weed and go up or down from there, but this also varies by state.
Here in Colorado, dispensary shelves are full of flower that is 20-28% and most of the homegrown cannabis I’ve tried is on par with those high THC percentages.
In states like Colorado, Oregon, Washington and California, the average THC is atypically high. I was gifted cannabis grown by my neighbor and approximated 15% THC, at first, based on the national average. But, after testing and making an infusion with it, I realized it felt much stronger than the dosage math suggested. I adjusted it to 25% for future batches and it felt much more accurate.
In states where cannabis is still prohibited, the percentage of THC could be in the 10-20% range.
Estimating THC in weed based on visual cannabis quality
While we can’t know the exact percentage of the THC in your cannabis just by looking at it, you can use these estimates to get you in the ballpark so you can do dosage math.
Low Quality “Shwag” and Brick Weed: 3-5% THC
Shwag/Brick Weed has very few trichomes on it. It’s not sticky, is typically brittle, and smells like grass and clay. If you can avoid it, avoid it.
Trim and Shake: 5-20% THC
This is the leftover plant material from manicuring cannabis or can be the broken flowers that fall into the bottoms of bins and bags.
Don’t underestimate the potency of trim and shake. If it contains more fan leaves and fewer trichomes it may be on the lower end of the spectrum. If it’s covered in resin, it can be very high in THC.
“Mids”, Novice Homegrown, Balanced Ratio Cannabis – 10-17% THC
The US average is right in this range. Mids are great to cook with and typically have a lower pricepoint than top shelf dispensary weed.
Dispensary and experienced homegrown – 12-25% THC
While some dispensaries carry lower THC cannabis, the lowest I’ve seen here in Colorado this year was 12%.
An experienced home grower who has carefully selected their genetics, will likely choose something that’s more likely to produce a higher THC content, if that’s what they’re going for.
Top shelf dispensary cannabis and expert homegrown – 25%+
Because most of the compounds in cannabis are concentrated in the resinous trichomes, a good way to know if it’s higher in THC is if it’s the sticky-icky.
Flower covered with crystals, bursting with terpenes that make it smell like pine, citrus, or skunk
Over time, as you keep making cannabis products, this will get easier. Just remember that all cannabis is different, so you’ll go through this process each time you change your plant material.
If you’d like more consistent medicine, making bigger batches can be helpful. I like using the FX to create large batches when I know I want to test something for a longer period of time or if I’m making medicine for my friends and family.
Can you estimate CBD or CBG in weed?
In short, no. Because it doesn’t have the noticeable physiological effects in the same way that high THC weed does, there’s no way to cross reference if your dosage math is in the ballpark. When working with CBD or CBG plant material, it needs to be lab tested. I buy my CBD and CBG flower from Sacred Smoke.
Free THC dosage calculator
Over the years, we’ve gotten so many questions about dosage math, that we designed a free dosage calculator to help you measure the amount of THC, CBD and now CBG(!) in your homemade edibles, tinctures and topicals.
We just finished adding some new functions to the calculator. You’ll now get a free dosage math mini-class when you sign up for free lifetime access to the calculator.
After the update, the dosage calculator can:
- Toggle from imperial to metric so if you’re not in the US you don’t have to curse us for using measurements like cups and teaspoons
- Calculate all of the cannabinoids that are widely available in plant material: THC, CBD and CBG
- Be used on mobile without you having to rotate the screen
So now, doing cannabis dosage math is even more convenient and simple.
As a new home grower in Colorado, two plants of LSD and one of white widow all from seed, dried, and decarb’d I am pleased to find your site. Do your calculations take into account the degradation you mention from decarboxaltion and from extraction when I infuse in coconut oil? As down adjusting by 0.9 for the decarb and 0.6 for the extraction gives very different numbers.
Thanks in advance, lydia