My Candle Uses a 70:30 Blend of Two Fragrance Oils Costing ₹3,000 and ₹6,000 Per Kg — How Do I Calculate the Fragrance Cost Per Candle?

The blend has one rate, and it is not the average

A blend is a new ingredient with a price of its own, and that price is a weighted average: each oil's rate multiplied by its share of the weight, added together. On your figures, 70% of the blend is at ₹3,000.00 a kilogram, which contributes ₹2,100.00, and 30% is at ₹6,000.00, which contributes ₹1,800.00. The blend is ₹3,900.00 a kilogram, or ₹3.90 a gram. Write that one figure into your cost sheet and never touch the two bottle prices again while costing this scent.

The instinct to average the two prices is strong and wrong. ₹3,000.00 and ₹6,000.00 average to ₹4,500.00 a kilogram — which is the correct rate for a 50:50 blend, and only for a 50:50 blend. Using it on your 70:30 mixture puts ₹9.60 of cost into every candle that does not exist, ₹960.00 across a hundred. That error is not harmless just because it is conservative. It pushes your price up, makes a viable product look marginal, and hides where your money actually goes.

There is a useful sanity check built into the arithmetic: the answer must always land between the two rates, closer to whichever oil dominates. Your blend at ₹3,900.00 sits below the midpoint because the cheaper oil is the bigger part. If your result is outside the two rates, or on the wrong side of the midpoint, the shares are the wrong way round. And the shares must sum to 100: a 70:30 blend that is really 70:30:10 because you topped it up with something is not a two-oil blend any more, and needs the same arithmetic with three terms.

From a rate per kilogram to rupees in the jar

Fix the load convention before you multiply anything. A fragrance load is a percentage of wax weight — that is how CSI product pages state it and how this series costs everything — so a candle holding 200 g of wax at 8% takes 16 g of blend and 216 g goes into the jar. That is the reading carried through every figure on this page. Sixteen grams at ₹3.90 a gram is ₹62.40.

If your "200 g candle" means the finished candle weighs 200 g, the wax and blend have to add to 200 g between them: 200 ÷ 1.08 gives 185.19 g of wax and 14.81 g of blend, and the fragrance line is ₹57.78 — ₹4.62 lower. Neither reading is wrong. Mixing them inside one workbook is.

Once you have ₹3.90 a gram, every other size is the same multiplication, and the load is the lever with the most force in it. Check your wax's stated ceiling before you move: Luxury Soy Wax CSI 464 states a maximum of 10% of total wax weight, and both oils in the CSI pair below state soy use up to 10%. When you blend, the binding figure is the lowest stated range among the components and your wax's maximum, whichever is lower — a blend does not inherit the more generous of the two.

By weight, not by drops

Every figure on this page assumes 70:30 by weight. That matters because the easiest way to mix two oils is to count drops or to eyeball two lines on a jug, and neither gives a weight ratio. Drop size changes with the viscosity of the oil, the bottle it comes out of, how hard you squeeze and how warm the room is — and Indian workshop temperatures swing a long way between a February morning and an April afternoon. Two oils that behave differently in a dropper will not land at 70:30 by weight just because you counted seven and three.

Price the consequence rather than arguing about it. If your real mixture is 60:40 instead of 70:30, the rate is ₹4,200.00 a kilogram rather than ₹3,900.00, and the candle is ₹67.20 rather than ₹62.40 — ₹4.80 a candle, ₹480.00 across a hundred, on a difference you cannot see in the cup. The costing error is the smaller half of the problem. A blend that drifts also smells different from the one you tested and sold, which is the kind of inconsistency customers notice and cannot name.

The fix is ordinary. Put the cup on a scale that reads to 0.1 g, tare it, pour the first oil to its weight, tare again, pour the second. For a 16 g blend at 70:30 that is 11.20 g and 4.80 g. Mix the whole batch of blend at once rather than per candle — a hundred candles is 1,120 g and 480 g — because one weighing at batch scale is more accurate than a hundred small ones, and it gives every candle in the run the same scent.

The same arithmetic on two oils you can buy

Take British Rose at the 1 kg pack, ₹3,068.00, which is ₹3,068.00 a kilogram, as the 70 part, and Vanilla Bean at the 1 kg pack, ₹7,646.00, which is ₹7,646.00 a kilogram, as the 30. The blend is 0.70 × ₹3,068.00 + 0.30 × ₹7,646.00 = ₹4,441.40 a kilogram, or ₹4.44 a gram. Sixteen grams of it is ₹71.06, which is ₹8.66 more than your blend costs on your rates — a floral-and-vanilla pairing at CSI's prices is dearer than the pair in your question, and this page is not going to pretend otherwise.

What the two pages publish matters as much as what they cost. The British Rose page states soy use up to 10% of total wax weight, a flash point of 192°C and 0% vanillin with no discolouration or yellowing. The Vanilla Bean page states up to 10% for soy wax, a flash point of 203°C, 2.5% vanillin and potential discolouration, and advises testing with lighter wax. Blended, the load you may work to is the lowest stated range among the components against your wax's own maximum, whichever is lower — here both oils state 10% for soy, so the wax decides.

Flash points do not blend. They are a transport, storage and handling property, not a ranking of hot throw and not the temperature at which fragrance burns off in wax, and a mixture does not take the weighted average of two of them. The conservative practice is to work to the lower of the two rates you hold — 192°C on this pair — and to add fragrance in the usual 80–90°C window, which sits well below it. Where an oil publishes no flash point, ask on WhatsApp for documentation rather than assuming anything.

Buying a blend: packs do not divide by a ratio

Here is the part no blend calculator tells you. A hundred candles at 16 g need 1600 g of blend, which is 1120 g of the 70 part and 480 g of the 30 part. Neither number is a pack size. On the CSI pair you would buy British Rose as a 1 kg pack plus a 100 g and a 50 g — 1150 g for ₹3,622.60 — and Vanilla Bean as a single 500 g pack, ₹3,840.00. That is ₹7,462.60 of oil to make a blend whose theoretical cost for 1600 g is ₹7,106.24. The gap, ₹356.36, is what rounding up to the next pack costs, plus the fact that small packs carry a higher rate per gram.

You are also left holding 30 g of one oil and 20 g of the other, which is not waste if the scent repeats and is dead money if it does not. There is usually more than one way to cover the shortfall: two 15 g bottles instead of the 50 g pack covers the same gap for ₹3,599.00 in total, ₹23.60 less cash, at a worse rate per gram and with less oil in hand. Neither is wrong; the point is that a blend forces a pack decision on you twice over, once per component, and the decision is about cash and shelf life rather than about rate.

Delivery is the other half of buying two oils instead of one, and the honest answer here is that consolidating does not always save. The 1 kg British Rose pack stores a packed weight of 1.5 kg and the 1 kg Vanilla Bean pack stores 2.0 kg. Sent separately the published bands come to ₹360.00; sent together as one 3.5 kg parcel the band is also ₹360.00, so the saving is nothing at all. Consolidation pays when the combined weight lands in a band that costs less than the sum of the separate ones, and on this pair it does not. Check the bands for the weights you are actually sending rather than assuming one parcel is always cheaper. Rates are the published flat bands as at September 2026.

Costing your own blend, step by step

What the ₹62.40 does not include

₹62.40 is the fragrance in one candle and nothing else. The wax, the vessel and the wick are three more CSI lines and belong in your sheet beside it. Everything in the table below is real, is not a CSI product, and therefore gets no figure here. Total your sheet as materials from CSI plus your own costs, and keep the blank rows visible rather than rounding them into the fragrance line where they will never be found again.

One blank deserves a note on a blend page: the oil left in the mixing bottle. Decanting twice — once from each pack into the blend bottle, once from the blend bottle into the wax — gives the oil two more surfaces to cling to, and at ₹3.90 a gram a stubborn 5 g is ₹19.50 gone. Use a narrow bottle you can scrape, weigh what you decant, and set your own allowance once you have measured a batch. This page assumes none, which is an assumption and not a measurement, so ₹62.40 is a floor.

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