How Do I Calculate the Amount of Additional Wax Needed to Reduce a 10% Fragrance Batch to a Lower Target Concentration?

The formula, in three lines

Every dilution calculation rests on one fact: the fragrance oil already in the pot stays there. Remelting does not remove it, and you should never try to skim it off. What changes is how much wax surrounds it. So the arithmetic starts with the oil, not the wax.

Then recheck: oil ÷ new total weight should give your target. If it does not, find the slip before the wax goes in, not after.

This series always states fragrance load as a percentage of the total candle weight — wax plus oil. Every number on this page uses that basis. If your recipe uses a different basis, read the section on the wax-basis trap before you weigh anything.

Worked on a 10 kg batch at four targets

Take a 10,000 g batch of scented wax at 10% of total weight. It holds 10,000 × 0.10 = 1,000 g of oil and 9,000 g of wax. Here is what each lower target requires. The cost column assumes the batch was poured in Natural Soy Pearl Wax and prices the added wax at the 10 kg pack rate, ₹4,248.00 ÷ 10,000 g = ₹0.4248 per gram; the candle count assumes 150 g fills. Both are example figures.

Two patterns stand out. First, the extra wax grows faster than the drop in load. Going from 10% to 8% adds a quarter of the batch weight; going from 10% to 6% adds two-thirds. Second, you do not buy wax at the 10 kg rate unless you buy a 10 kg pack. For the 8% route you would buy a 5 kg pack (₹2,124.00) or three 1 kg packs (3 × ₹450.00 = ₹1,350.00) and keep the remainder.

Natural Soy Pearl Wax has no fragrance load published on its product page, so there is no stated ceiling to compare against. The decision between 9%, 8%, 7% and 6% is purely a test question: which is the highest load that stays dry in your storage and still throws the way you want.

The multiplier shortcut

If you dilute regularly, rearrange the formula into a single multiplier: wax to add = current weight × (current load ÷ target load − 1). It works for any batch size because it never asks you for the oil weight.

A batch of 3.6 kg going to 8% needs 3,600 × 0.25 = 900 g. A batch of 22 kg going to 7% needs 22,000 × 0.4286 ≈ 9,429 g. Keep the multiplier table on the wall beside the scale; it prevents mental arithmetic at a hot melter.

The wax-basis trap

Everything above assumes your 10% was a share of the total. Many recipes, and every CSI wax page, express load as a share of wax weight instead. If your batch sheet says '10%' and someone weighed 100 g of oil per kilogram of wax, the oil is not 10% of the batch.

Convert first. A wax-basis load W is W ÷ (100 + W) of the total. So 10% of wax weight is 10 ÷ 110 = 9.09% of the batch. A 10,000 g batch made that way holds 10,000 × 10 ÷ 110 = 909.09 g of oil, not 1,000 g.

Now the dilution changes. To reach 8% of total: 909.09 ÷ 0.08 = 11,363.64 g, so add 1,363.64 g of wax — not 2,500 g. To reach 7%: 909.09 ÷ 0.07 = 12,987.01 g, so add 2,987.01 g. Use the wrong basis and you over-dilute by more than a kilogram, which can leave a candle too weak and push you back towards adding oil.

The same formula at other batch sizes and starting loads

Nothing in the formula is tied to 10 kg or to 10%. It works for a 600 g test pot and for a 40 kg production melt, and for any starting load. Two more examples show how it behaves away from the round numbers.

A small test pot at 12%

Say a 1,500 g pot was mixed at 12% of total weight by mistake. Oil = 1,500 × 0.12 = 180 g. To reach 8%: 180 ÷ 0.08 = 2,250 g, so add 750 g of wax. The multiplier is 12 ÷ 8 − 1 = 0.5 — half the batch weight again. A 4-point drop from 12% costs proportionally more wax than a 2-point drop from 10%, because the oil you are spreading is larger.

A large melt at 9%

Say a 32 kg melt sits at 9% and your tests point to 7.5%. Oil = 32,000 × 0.09 = 2,880 g. Target weight = 2,880 ÷ 0.075 = 38,400 g, so add 6,400 g. The multiplier is 9 ÷ 7.5 − 1 = 0.2. Half-percent targets are perfectly usable; the formula does not care whether the target is round.

If your melter has a capacity limit, check it before you calculate. Diluting 32 kg to 38.4 kg may simply not fit in one pot. In that case split the batch, dilute each portion with the same multiplier, and recheck each portion separately rather than averaging them afterwards.

Before you trust the number

The formula is exact; your inputs may not be. Three checks keep the result honest.

When you add the wax, melt it fully and bring the combined batch back to your normal fragrance-mixing temperature, staying below the oil's published flashpoint, and stir thoroughly so the oil redistributes evenly through the new wax. Then recheck the arithmetic one last time on the batch sheet: oil ÷ total = target. If your pilot at the lower load still sweats, the arithmetic was never the problem — the oil and wax are not a good pair, and the next step is a different oil or wax, not a different number.

Where this page fits

CSI already has guides that cover parts of this question. This page answers one sweating decision; these cover the neighbouring questions:

Three things to buy for this fix

Frequently asked questions