What is the best diffuser base to fragrance ratio?

When making reed diffusers, figuring out the ideal base-to-fragrance ratio is an important step. Most reed diffuser base can hold up between 20 to 40% fragrance, depending on the brand. Our diffuser base can hold up to 50% fragrance, depending on the fragrance used. 

Knowing the maximum amount of fragrance oil a base can hold is helpful. However, just because a base can hold a lot of fragrance doesn’t mean you should always use the maximum amount. In many cases, you can get a good scent throw with less fragrance. This is often true for candles, lotion, soap, perfume, and other projects as well. 

The ideal diffuser base to fragrance ratio can vary depending on the fragrance you’re using. The amount of fragrance you can use may also be limited by the IFRA for certain fragrances. Below, learn more about finding the perfect fragrance oil to diffuser base ratio so you can start making amazing-smelling reed diffusers. 

How much fragrance can I use in a reed diffuser?

As mentioned earlier, our diffuser base can successfully hold up to 50% fragrance depending on the fragrance you’re using. However, there’s no need to use a 50:50 ratio of fragrance to base. This ratio would smell overpoweringly strong with most fragrances. 

The ideal diffuser base to fragrance ratio can vary with each fragrance. As a general rule, the ideal fragrance-to-base ratio for reed diffusers is somewhere between 10 and 20% fragrance. In other words, you will get a good scent throw by using 10% fragrance and 90% base, or 20% fragrance and 80% base for a stronger scent. 

Keep in mind that some fragrance oils naturally have a stronger scent than others. If using a fragrance with a very strong scent, you may find that you need less than 10% fragrance in your reed diffuser blend. 

Each fragrance oil also has different physical properties. For example, some fragrance oils are naturally more viscous (thicker) than other fragrance oils. Thicker fragrance oils tend to be more difficult to blend with reed diffuser base, which can make it challenging to make reed diffusers with a high fragrance load. If using a thick fragrance oil, start with a small amount of fragrance and work your way up. 

IFRA Limits for Reed Diffusers 

Before making reed diffusers, it’s important to review the IFRA certificate for any fragrance oil you plan on using. You can find the IFRA certificate for each NorthWood fragrance oil on its product page. 

The IFRA is a regulatory body that determines what percent of fragrance is safe to use for different applications such as lotion, perfume, shampoo, and more. Each type of project has its own category with different limits. Usage limits are different for each fragrance oil, and are based on the ingredients in each individual fragrance. 

If you’re new to IFRA certificates, this blog post is full of helpful information you might want to review. 

Reed diffusers are found under category 10A on IFRA certificates. Some fragrance oils will have a high limit, while others will have a low limit for reed diffusers. If a fragrance has a low limit, you should always use that number as the maximum percent to use – even if your base can hold more than that. Likewise, if a fragrance has a high limit, you should never use more fragrance that your base can hold. 

If a fragrance oil has a very low limit for reed diffusers (e.g. less than 5%), you can still experiment with using it in a diffuser. You may find that some fragrances still work great in diffusers even when using a low percent. 

Testing is the Key

As with any project, testing is the best way to determine the best fragrance to reed diffuser base ratio. Making a small test batch is the most economical way to determine if your reed diffuser will perform the way you want. When testing, it may be helpful to make a few batches with different fragrance loads. For example, you might make blends with 10% fragrance, 15% fragrance, and 20% fragrance to compare how each one works. 

Remember that each fragrance oil is different. You may find that some fragrances work best at 10%, while others work better at 15 or 20%. We recommend keeping notes so you can remember the ideal ratio for each fragrance oil you use in your diffusers.