How Do I Calculate Fragrance Oil Reorder Quantities Using Monthly Candle Demand, Supplier Lead Time and Remaining Raw-Material Shelf Life?

Three inputs, two outputs, one cap

Most reorder rules answer two questions: when to order and how much. For candle fragrance oil you need a third answer as well, because oil is not a jar or a wick that keeps indefinitely in a carton. The question is how much you can hold before the oldest kilogram has been in storage longer than you have evidence for. So the method on this page uses three inputs, all of them yours: monthly demand in grams, your real lead time, and the remaining months you can show the oil stays acceptable. From those it produces a reorder point, an order quantity and a holding cap that the order may never break.

Getting the inputs right

Monthly demand

Convert candles into grams. A 200 g candle at 8% fragrance load by total weight holds 16 g of oil and 184 g of wax. Monthly oil demand = candles per month × 16 g. Use the last few months of actual pours, and treat a festive peak as a separate plan rather than averaging it in.

Lead time

Lead time is not just delivery. It runs from the day you decide to order to the day the new lot is approved for production: placing the order, payment, dispatch, transit, your incoming check of appearance and odour against a retained sample, and any confirmation candle with its cure. CSI publishes no lead times, so measure your own from past orders and use the longest recent one, not the best.

Remaining acceptable months

This is the input most reorder sheets leave out. It is the number of months you can show, from your retained oil samples and test candles, that the oil stays acceptable in your storage, minus the age of the stock you already hold. CSI fragrance-oil pages publish no shelf life or storage conditions; ask on WhatsApp (+91 7397976926) for the IFRA certificate, MSDS and any storage or shelf-life guidance for that oil and lot, and keep the reply in writing. Until you have both, use the shortest period you have tested.

The formulas

Reorder point = monthly demand × (lead time in months + safety months). When stock falls to this level, order.

Order quantity = monthly demand × the months you want each order to cover, rounded up to whole packs.

Holding cap = monthly demand × tested acceptable months. Stock on hand when the order lands, plus the order, must stay at or below this cap. If it would not, order less, more often.

Worked example: Woody Oud at 1,000 candles a month

A maker pours 1,000 Woody Oud candles a month at 200 g and 8%. The lead time, safety stock and tested months below are example figures, standing in for the maker's own.

At the 1 kg price, the order costs 16 × ₹4,531.20 = ₹72,499.20. Doubling the order cycle to two months would cost 32 × ₹4,531.20 = ₹144,998.40 and still pass the cap at 8 + 32 = 40 kg. The cap says that is allowed; your cash position decides whether it is wise. No pack above 1 kg is listed, so a larger order is simply more 1 kg packs at the same listed price or a WhatsApp quote. There is no published bulk discount to justify buying further ahead.

The same method for a slow oil

Now take Gardenia Tuberose at 50 candles a month: 50 × 16 g = 800 g a month. With the same example lead time and safety stock, the reorder point is 0.8 × (0.5 + 0.5) = 0.8 kg. Suppose this maker has tested Gardenia acceptable for only 3 months, so the cap is 0.8 × 3 = 2.4 kg. When the order lands, about 0.4 kg remains. Ordering 2 × 1 kg packs (2 × ₹4,332.00 = ₹8,664.00) brings stock to 2.4 kg, exactly at the cap. Ordering 3 kg would break it. The method has quietly told the maker to buy two packs, not five.

One handling note for this oil: its product page states a flashpoint of 98°C and says to add it below 98°C, so check your add temperature with a separate thermometer.

When the stock you already hold is ageing

The cap above assumes all the stock you hold is equally fresh. Often it is not. Suppose the 8 kg of Woody Oud left when the order lands comes from a lot that has already spent three of its four tested months in your store room. That 8 kg has about one month of evidence left, and at 16 kg a month it will be used within about two weeks, so it is fine. But if demand dipped and the same 8 kg would take two months to use, half of it would outlive the evidence.

So add one more check for the oldest lot: kilograms of the oldest lot ÷ monthly demand must be less than its remaining tested months. If it is not, either pour that lot faster, test it beyond its current evidence before using the tail end, or delay the new order so the old lot is not pushed to the back of the queue. Never pour new and old lots into one container to hide the problem; record them separately and use the oldest first.

Running the rule every week

Buying honestly

This rule will sometimes tell you to buy less than you would like and more often than is convenient. That is the point. A slightly higher ordering frequency costs some admin; oil that outlives your evidence costs product, customer trust and the work of testing it. Order whole 1 kg packs for high-use oils, consider 500 g packs where the cap is tight, and never let a reorder sheet promise customers a fragrance that stays unchanged.

Where this page fits

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

Three things to buy for this decision

Frequently asked questions