How Many Drops of Essential Oil in a Diffuser? (100 – 500 ML Chart)


Using an essential oil diffuser in your home is not usually just for aromatherapy reasons. Aromatherapy has fantastic benefits for your physical and emotional health, but sometimes, it’s fun to scent your home just because you enjoy the scent.

Are you wondering how many drops of essential oil to add to your diffuser? The number of drops of essential oil that should be added to a diffuser depends on the size of your diffuser. As a general rule, put 3-6 drops of essential oil per 100ml of water.

This chart tells you how many drops you need for your ultrasonic diffuser:

VolumeDrops of Essential Oil
100 ML Diffuser3-5
200 ML Diffuser6-10
300 ML Diffuser11-15
400 ML Diffuser16-20
500 ML Diffuser21-25

If you are using a nebulizer diffuser, it’s waterless and you need to add 15-25 drops of essential oil in the bottle.

add oils

If you have your diffuser and your favorite essential oils ready, you can add water and your oil and relax while being surrounded by your favorite scent.

So, if you are still gathering what you need or facing lingering questions about what to buy, it helps to evaluate what you need before you start shopping.

What Size Diffuser Do I Need?

Size matters in the world of diffusers. Factoring into this decision is how large your room is and how long you want to run your diffuser, so the scent permeates all corners of your space.

Large Room Considerations

  • A large room with minimum airflow will need a diffuser with a powerful motor because it needs to circulate the scent being diffused.
  • Be sure to find a diffuser that has a larger reservoir because, the more water there is, the longer it can run to fill a large space with scent.
  • Consider finding a water tank in the 500 ML to 800 ML range to accommodate a large room.

Read our full article on Best Essential Oil Diffusers for Large Rooms.

Medium to Small Room Considerations

  • Too large of a diffuser can overwhelm a small space with scent.
  • Be sure to find a diffuser with a small to medium reservoir to accommodate the size of your room.
  • Consider a tank in the 100 ML to 300 ML range to accommodate the needs of your smaller space.

How Does a Diffuser Work?

A diffuser works by having a vaporizer at the bottom of the holding tank that vaporizes the water and oil and releases them from the top of the tank as a mist. It works as a cool-mist humidifier. When you add oil to the water, it gets mixed in with the water, and when released with the vapor, it scents your room.

What Are Essential Oils?

Essential oils are oils extracted from plants by distillation. They are called essential oils because they are from the essence of the plant. When the essential oils are extracted from the plant, they are potent. They are often used for aromatherapy, which is the use of scents to improve health and well-being.

Does It Matter What Kind of Oil I Use in My Diffuser?

The quality of the oil you choose for your diffuser matters. Essential oils can be expensive but using oil that is not toxic is important. You will want to look at the ingredients label and make sure that the plant’s botanical name is listed and that it does not include any other ingredients such as fragrances.

As long as you are confident about the quality of the oil, you can buy any brand. You do not have to purchase oils in the same brand as the diffuser you own.

How Many Drops Are in My Bottle?

Since essential oils are expensive, it helps to know how much use you will get out of each bottle of oil. You have to take into consideration how large your room is, too.

After thinking about the chart above for drops according to water reservoir size, you can calculate how long a bottle will last. The following chart tells how many drops of oil are in the different sizes of bottles:

Bottle SizeDrops
.3 milliliters6
.5 milliliters10
.6 milliliters12
1 milliliter20
1.25 milliliters25
2.5 milliliters50
5 milliliters100

Mixing Essential Oils in a Diffuser

You have the option of mixing your essential oils when you add the oil to the diffuser. To do this, you should consider how to best group your oils for the aromatherapy purpose you are trying to achieve.

For instance, if you want to have a calming experience with your diffuser, you might use both lavender and jasmine essential oils. If you would also like to reduce your anxiety, you can add orange essential oil to your lavender and jasmine.

Sometimes you may want to layer flowery scents or herbal scents. All you have to do is find a combination and aroma that suits your needs.

There are some essential oil blends for work day. And essential oil blends for Sore Throat.

Can Essential Oils Be Bad for You?

You have to remember that, even though essential oils are natural, they are very concentrated and can even be toxic, especially for children and pets. There are certain issues you need to take note of before you begin using essential oils in your home.

  • Some essential oils are toxic. Some symptoms of toxicity include:
    • Drowsiness
    • Seizures
    • Shallow or slow breathing
    • Digestive upsets
    • Skin irritations
    • Irritated or red eyes
  • You never want to apply essential oils directly to the skin without diluting them.
  • Before ingesting any essential oil, consult with a healthcare professional.
  • Those with asthma may have a reaction to the particles of essential oils diffused into the air.
  • Headaches may be caused by too much exposure to the essential oil in the air.

What If I Add Too Much?

If you add too much oil to your diffuser, you may notice headaches or skin irritations. If you find that you added too much oil and you do not want to waste the oil you used, pour the contents of the diffuser’s water reservoir into a glass container. (You want to use glass so you can clean it without lingering scents.)

Then, all you have to do is dilute your mixture with more water and pour it back into the diffuser.

If you are new to using oils, it helps to start out with a conservative amount of oil drops and go up from there until you find what you prefer.

Can I Leave My Diffuser on Overnight?

Leaving a diffuser on overnight is not recommended. Essential oils are rather potent and saturating the air for too long can cause problems, many of which are noted above. Additionally, if you are sleeping and your diffuser is running, you have no way of knowing if the level of essential oils in the air is toxic.

How Long Should I Run My Diffuser?

Your diffuser will come with instructions for the recommended timing of usage. Many diffusers even come with timers if you forget to shut it off.

There are diffusers on the market that are powerful enough to fill a room rather quickly. These diffusers will have a shorter recommended run time. Those that run slower diffuse at a slower rate, meaning they run for longer without potential risks.

To Conclude

Using a diffuser is a wonderful way to relax and lift your spirits. Aromatherapy has been used for an incredibly long time to help with mental clarity and well-being.

After some careful planning and considerations for room size and what size diffuser will work with your space, you only need to decide how much and which oil to use.

If you start out with less oil in your diffuser, you can avoid complications from having used too much. By building up to the perfect number of drops, you will hit the perfect level of scent every time you turn on your diffuser.

Grace Young

I love candles! I have personally tried over 100 brands of candles. The total burn time of these candles is over 5000 hours. I also talk about essential oil diffusers and reed diffusers. Essential oil diffusers and diffusers are also an important part of the scent in my home.

Recent Posts