How to Use Our THC Calculator Guide

Wondering how to calculate how much THC is in your edibles? We have a weed potency calculator that can tell you!

The potency of edibles and infused oils depends on a few factors:

  • how much THC was in your weed to start with
  • how much weed you used
  • if it was water cured
  • what you infused with it
  • how many ounces of product you infused into

Starting THC amount

If you bought your material at a dispensary, you likely know this number. Or if you know the name of the strain you might be able to google the amount of THC in it.

If you acquired your weed through less than legal means, you’ll have to just ballpark it. Average black market cannabis in illegal states is about 15%.

If you’re using Volcano leftovers, again you’ll have to ballpark it as it depends on how thoroughly used the material is and of course what its initial THC level was. But we’ve seen ABV / AVB as high as 9%, so that can give you an idea.

Starting weight of product

The next thing you need to know is how much weed you used in your edibles. Again, if you bought it from a dispensary you will likely know the weight in either grams or ounces, and you can trust that the weight is accurate.

If you acquired it elsewhere, the measurements may or may not be known, nor perfectly accurate.

If you know the weight in ounces, you’ll need to convert it to grams to use our calculator. Here are some common weights converted, or for other weights you can use Google’s conversion tool.

  • 1 oz = 28.34 g
  • 1/2 oz = 14.17 g
  • 1/4 oz = 7.085 g

Water curing

Water curing is relatively simple and involves soaking your material in water for a few days. Doing so actually alters the chemical construction of it.

While it doesn’t directly remove THC, it’s believed some loss occurs due to the trichomes falling off in the water. Trichomes are the little “hairs” that cover the leaves and flowers of the cannabis plant. Trichomes contain cannabinoids like THC and CBD, so when they fall off, the plant does lose those cannabinoids. The effect is minimal, but something, and that’s why we include this in our calculator.

The benefit of water curing is that it can help dilute the strong cannabis flavor. Trichomes also contain terpenes, which are responsible for giving weed its signature scent and flavor. But just because we’re cooking with weed doesn’t mean we want our food to taste like weed! If this is something you’ve been dissatisfied with when making edibles in the past, try water curing your material first.

The solvent

The solvent is what you mix your weed into — so, the oil, butter, vegetable glycerin, etc. There are of course other options as well but these three are the most common so that’s what we have included in the calculator. Select the option that’s closest to the product you used.

Different solvents have different rates of extraction. Coconut oil and olive oil seem to extract the most THC. Anecdotal evidence can vary, however, and to our knowledge no legitimate study has been done on this to really know for sure which solvent extracts the most THC.

Solvent amount

The last thing you need to enter into the calculator is how many fluid ounces of solvent you used. This is the measurement taken before you infused your cannabis into it. So, if you used an 8 oz jar of coconut oil, put 8 oz — don’t worry about measuring out your end result.

  • 2 cups = 16 oz
  • 1 cup = 8 oz
  • 1/2 cup = 4 oz

One more thing to note

Our calculator assumes that you will be using decarboxylated cannabis. Decarbing your weed is widely considered to be an essential step in getting the most potency out of your cannabis for edibles. If you’re not familiar with decarbing, we have an article about how to decarb weed for cooking.

Getting your result

Once you enter in all the data, we’ll give you your result. The first number we’ll give you is the total milligrams of THC in what you made. The next numbers are the breakdown of how much THC there is in a single ounce, tablespoon, and teaspoon of what you made. This will help you know how much THC you’re adding to a dish or recipe.

The next section is similar, and optional: we ask how many cups of your product you’re going to use in your recipe. You might use half a cup of butter to make cookies, so enter in 0.5. Next we ask how many servings your recipe will make — basically, are you going to eat all the cookies or split them into one dozen servings? Depending on the size of your serving, our calculator will tell you how much THC someone is actually going to get from a single serving of your edibles.

THC potency vs. tolerance

Keep in mind that everyone’s THC tolerance is different — so what’s potent to your friend might not feel as potent to you. As such, whatever result you get should be used as a guideline, and any edibles you make for the first time should always be ingested slowly until you get some context for how different potency levels affect you personally.

Some number in milligrams isn’t going to mean anything to you the first time you try an edible. But afterwards you can compare that number with your experience to get a feel for what the THC potency levels mean relative to your personal THC tolerance. And remember, your experience may be different from someone else’s!

Making edibles can be a fun and addicting way to enjoy your cannabis. And with so many strains, oils, and recipes to try, the possibilities are endless. After you make an infusion and get your results, you can select the option to have the results emailed to you. Then you can save it for later reference so you’ll know the weed potency the next time you make the same infusion.

Happy cooking!


  1. J on March 23, 2022 at 11:58 am

    What formula did you use to calculate? Just trying to understand how you came to the figures

    • Volcano Tips on March 31, 2022 at 5:16 pm

      We calculate the total THC in the material, and adjust for the solvent used based on our research and experience, then divide that by servings. It’s an imperfect science given how many variables are at play.

  2. jean on February 1, 2022 at 10:58 am

    I needed this information. Many thanks.

  3. Angela Noyes on August 5, 2021 at 7:08 am

    Hello! I have to say that I love this calculator! I’ve been using it to get my into of mg per gram of flower but instead of using it for edibles-I take the end number and divide by two (50% is lost in smoking flower) and that’s a decent estimate of how much thc/CBD is being consumed. I’ve been able to do this with consistent results for over three years now. I would love to have another calculator that puts consumption as one of the variables also. If anyone is interested in creating such a calculator-please contact me because I would be over the moon excited to try it out and share it with my peers! Thanks!

Leave a Comment