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Blog | CBD

Find Out How Much CBD Is In Any Bottle In 60 Seconds!

When first looking at or starting to use CBD (cannabidiol) oil, many people become confused with percentages over milligrams and struggle to quickly decipher how much cannabidiol a bottle contains and in parallel also often ask how long does a bottle of CBD oil last?

Given the lack of standardisation in this market, there isn’t one single way to label bottles of CBD oil, and this can make comparison difficult. 

Sometimes you look at two bottles of oil and find they have the same percentage on the label but contain vastly different amounts of CBD extract in the bottle…Confusing, we hear you.

This is why we have developed a quick tool, and you can skip to the end of this post to use it, but all of what we are going to discuss here will be useful if your using CBD, so keep reading!

what do you mean

You might be thinking, what? How can the same percentages contain totally different amounts of CBD?

The answer lies in the way some brands market CBD oil, it’s important to disregard the percentage and only look how many milligrams of CBD are in a bottle, as the milligram amount doesn’t flex with bottle size.

So what is a milligram, and how do I compare CBD oil strength of any bottle regardless of the label?

Let’s take a look:

Milligram to Gram

So we will start from the basics. Let’s quickly run through the definitions so we are acquainted:

Firstly, let’s compute the milligram to gram calculatution. One thousand milligrams equal one gram, and by switching the numbers around  you can work out the opposite if required, gram to milligram. Where, one gram gram equals one thousand milligrams.

CBD Dosage Chart

How strong is a bottle of CBD Oil

Calculating CBD Concentration

To work out the milligrams of CBD in a bottle, all you need is to check how large the bottle is and the percentage of CBD in the bottle.

These are usually denoted on the label and you can either calculate the milligram content yourself or use the tool below to do the work. Should you wish to to learn how to do it yourself, follow the steps below:

(Bottle Size (ml) x CBD Percentage (%))*1000 = CBD concentration in milligrams

For example lets compare 5% CBD oil in a 30ml bottle and 10ml bottle, to work out cannabidiol content in each bottle.

30ml: ((30ml*0.05)*1000)) = 1500mg CBD

10ml: ((10ml*0.05)*1000)) = 500mg CBD

As you can see, bottle size makes a huge difference, you might have noticed the larger the bottle the incremental increase in CBD concentration moves in at the same speed (in mathematical terms, it’s linear).

If looking at the above is confusing you, don’t worry and just use the tool we built for you below!

CBD Concentration Calculation Tool

Calculate CBD Strength


How long does a bottle of CBD oil last?

This is quite an open ended question.

For most people a bottle lasts between 3-6 weeks but there are a number of factors to consider, and it varies on your own personal usage.

Instead track your usage over a week, and answer the questions below to easily figure out how long a bottle will last you:

  • How many drops are you using daily? Note – only answer this when you have found your ‘sweet spot’ dose.
  • How big (ml) is your bottle?
  • How much CBD (mg) is in a bottle?

Calculate how long a bottle of CBD oil lasts

We have built a couple of quick tools to answer this question for you, depending on bottle size use the form most relevant for you.

Note, these calculations assume the bottles contain the average number of drops.  Some contain a slightly high number, even for the same bottle size. 

Use our tools below as a rough guide, until you know how many drops are in your bottle for sure!

How long will a 10ml bottle of CBD oil last?

Fill in the first two boxes below and let us do the work!


How long will a 30ml bottle of CBD oil last?

Fill in the first two boxes below and let us do the work!


Doing it manually

Most 10ml CBD tinctures contain between 200-220 drops, and most 30ml ones contain between 600-660 drops.  

When you have this info, follow the steps in the example below:

  • Assuming we are using a 10ml bottle of  470mg CBD Oil.
  • We are using 10 drops a day.
  • The bottle contains 200 drops and each drop is 2.35mg CBD.
  • Our daily dose is 10 x 2.35mg = 23.5mg
  • Hence a bottle will last around 20 days (200 drops / 10 drops a day or 470mg / 23.5 = 20).