Fir Oil Usage Rates: Percentages in Drops and Grams
Recipes love percentages. Kitchens run on grams, drops and the scale you have. Here is how to move between them with fir oil, and which ranges to hold in your head while you do.
Fir Needle Essential Oil
Our own Fir Needle Essential Oil, in sizes from 0.5 oz to bulk.
From $10.99
Shop Now →From percent to grams
A usage rate is grams of oil per 100 g of finished product, so 1% of a 100 g lotion is 1 g of oil. The batch of fir oil behind our published Certificate of Analysis has a relative density of 0.924, so 1 g is about 1.08 ml, and at the rough convention of 20 drops per ml (drops vary, so weigh when you can), that is about 22 drops.
| Finished weight | 1% oil | 2% oil |
|---|---|---|
| 100 g (a lotion jar) | 1 g, about 22 drops | 2 g, about 43 drops |
| 113 g (a 4 oz bar of soap) | 1.13 g, about 24 drops | 2.26 g, about 49 drops |
| 454 g (1 lb) | 4.54 g, about 98 drops | 9.08 g, about 197 drops |
Skin oils work the other way round, by volume. Adding about 0.15 ml (roughly 3 drops) to 30 ml of carrier gives close to 0.5%, which is the low end of the 0.5% to 2% we recommend for general skin use, with a patch test first.
Ranges worth knowing
The Tisserand Institute publishes use-based ranges that apply to essential oils generally: 0.2% to 1% for sensitive or impaired skin, 0.5% to 1.2% for facial products, 1% to 3% for body oils and lotions, and 2% to 4% for bath and wash-off products including soap. We would start at the low end of whichever range fits and move up only if you want a stronger scent. More oil does not mean a better product.
For soap, one maker's chart lists fir needle at about 13 g per pound of oils (around 3% of oil weight). That figure is a general soap-making reference, not a rule for any particular oil, so treat it as a place to start.
Where IFRA fits
The fragrance industry's standards body, IFRA, publishes category-based limits for individual fragrance ingredients, and suppliers issue certificates against them for finished mixtures. Whether a limit exists for a given material, and what it is, depends on the exact oil and the current amendment, so we do not quote an IFRA number for our oil. If you sell what you make, ask each supplier for the documents that cover your product type, and when several limits apply, follow the lowest. For our own oil, ask in writing through the wholesale page or contact page before ordering, and we will tell you plainly what we have.
Good habits at the scale
- Weigh the oil rather than counting drops once a recipe matters.
- Write the percentage and the oil's batch number on your recipe card.
- Candle and room-scent suppliers publish their own ranges; a fragrance oil sold for candles, for example, lists 3% to 10%, but that is a different product from a single essential oil, so do not carry it over.
- Try a small batch before a big one.
Our dilution and patch test post has a drops table for skin oils, the melt-and-pour recipe covers the base-maker side of soap, and the formulating guide covers the order of decisions.
A few minutes with a scale and these ranges turns a vague recipe into one you can repeat, which is the whole point of knowing the numbers.
Fir Needle Essential Oil
Fir Needle Essential Oil from our own shop, in sizes from 0.5 oz to bulk.
From $10.99
Shop Now →