# Learn how to Make THC Oil for Vape Pen – The Definitive Information To calculate how much THC is in the oil you’ve made for your vape pen, you’ll just need to complete a simple formula. That’s the same as figuring out the levels of THC in edibles, too. First, you’ll need to determine how much THC is in the strain of the flower you used to make the oil. You can use our handy THC percentage chart here, or if purchased at a licensed dispensary, the package should note the amount.

It’s also crucial to know how many cups of liquid that your THC oil ended up being. Once you have those estimates or exact numbers, you’ll complete the following math –

Divide your THC % by 100Multiply that answer by 1000Multiply that answer by the number of G’s used in the mixtureDivide that answer by the number of carts that the oil can make to equal your per cart THC %

As an example, we’ll say we used 6 g of Bruce Banner at 25% THC, and you have 25 vape carts to fill.

25% ÷ 100 = .25 THC per g X 1000 = 250 mg THC x 6 g = 1,500 MG THC ÷ 25 = 60 MG per vape cart

Once you know the formula, you can use this simple math to figure out THC’s calculation when infused into other substances or liquids. 