A Cheaper Jar Saves ₹15 Per Candle but Increases Shipping Breakage — How Do I Calculate Whether the Cheaper Container Actually Reduces Total Cost?

Cost per delivered candle, not cost per candle

The reason this question feels hard is that most sheets cost the candle you made. Breakage is a fact about the candle you delivered, and the two are different numbers. If you pour a hundred candles and five arrive broken, you have to make five more to deliver a hundred, so the hundred you invoice are carrying the cost of a hundred and five. Write it as a multiplier and the whole thing collapses into one line: cost per delivered candle = candle cost × (1 + breakage rate), plus whatever it costs you to send each replacement.

This page uses the single-replacement form on purpose. It assumes each broken candle is remade and sent once, and that the replacement arrives intact. That is a simplification — at a high breakage rate some replacements break too — but it keeps the arithmetic honest and readable, and at the rates a real maker sees it is within a rupee or two. State it in your own sheet the way it is stated here, because a reader who does not know which model you used cannot check your number.

Three places a jar breaks, three different bills

Most people run this comparison with one breakage number, and that is where the sheet goes wrong. Glass breaks at three points in a candle’s life and the bill is different every time. Separate them before you count anything, because a jar that arrives cracked from a supplier and a candle that arrives cracked at a customer are not the same problem and do not have the same cure.

The third row is the one that changes decisions. A candle broken on your own bench costs ₹155.88 and nothing else — annoying, countable, done. A candle broken in transit costs ₹155.88, plus a second outbound parcel, plus the packing time, plus a customer conversation, and in a small D2C business the last of those is usually worth more than everything above it. If your cheaper jar is breaking in transit rather than on the bench, the 9.62% figure on this page is generous to it by a wide margin.

The breakage rate at which ₹15.00 disappears

With the dearer jar breaking nothing, the cheaper jar wins while the cost it adds through breakage stays under the ₹15.00 it saves. Breakage adds breakage rate × (candle cost + replacement cost), so the break-even is ₹15.00 ÷ (candle cost + replacement cost). Counting materials alone, that is ₹15.00 ÷ ₹155.88 = 9.62%. Add a replacement cost equal to the candle and it becomes 4.81%. Add more and it keeps falling. There is no version of this sum in which the answer rises.

Read the second column and the third together. Your ₹15.00 is gone between the 5% and 10% rows — at 9.62% exactly — and at a 10% breakage rate the cheaper jar is ₹0.59 worse per delivered candle than the jar it was supposed to undercut. Across a 300-candle run that is the difference between ₹49,101.57 at a 5% breakage rate and ₹46,763.40 with nothing breaking, a gap of ₹2,338.17 against a total saving of ₹4,500.00. Breakage does not nibble at a vessel saving. It eats it in two or three units.

CSI’s two jars, and why ₹59.80 is not a like-for-like saving

Your ₹15.00 is a like-for-like figure: the same candle, two vessels, one cheaper. The two CSI jars named on this page are ₹59.80 apart, and most of that gap is not glass quality. Black Glass Jar with Black Lid (150 gram) publishes a fill capacity of about 150 gm, a height of about 8 cm, an outer rim of about 7 cm, a base of about 6.5 cm, a metal lid and a hot-pour limit of 85°C. Yankee Glass Jar 130 ML publishes a clear cap with a tight seal and describes itself as suited to votives and sample sizes; it publishes no fill capacity at all. They are different sizes doing different jobs, so ₹59.80 is a specification difference, not a discount.

That matters for this sum in a specific way. If you swap down to a smaller vessel you also pour less wax, so your candle cost falls on two lines at once and the comparison stops being about breakage at all. Hold the contents constant — the same ₹108.68 of wax, fragrance and wick — and you are comparing vessels honestly; change the pour weight as well and you are comparing two products. This page holds the contents constant and prices the vessel per piece, and it does not claim that a 140.4 g pour fits either container.

The honest like-for-like comparison at the larger size is between two jars that publish the same capacity. Black Glass Jar with Black Lid (150 gram) is ₹107.00 a piece at ten and Clear Glass Jar with Golden Lid is ₹94.40 a piece at ten, a difference of ₹12.60, and both pages state a 150 g fill capacity, an 8 cm height and a hot-pour limit of 85°C. That is the kind of pair on which a breakage comparison means something, because the only variable left is the glass.

The one leg you can price exactly: glass coming in

Everything downstream of your bench is your own cost. Everything upstream of it is priced on the store, and it is worth pricing because inbound freight is where cheap glass quietly stops being cheap. CSI bills by the stored packed weight of what you order, against published weight bands, and a jar that costs ₹47.20 does not arrive for ₹47.20.

Two things fall out of that table. First, the ₹47.20 jar lands at ₹65.20 when you buy ten, because ₹18.00 of parcel is riding on each one — 38.14% of the jar’s own price. Landed, the gap between the two vessels is ₹68.80 rather than ₹59.80. Second, buying in fifties rather than tens drops the parcel share to ₹16.00 and ₹24.00 a jar, a difference of ₹2.00 and ₹3.00. That is not a rate discount on the glass — CSI’s jar prices are the same per piece in both cases — it is purely the weight band doing its work.

What this page will not put a number on

Cartons, mailers, bubble wrap, void fill, printed labels, ribbon, outbound courier to your customer, replacement freight, payment gateway refunds, packing time and the sale you lose when a customer receives glass in pieces are all real costs of breakage. None of them is a CSI product, none is published on the store, and none gets a figure here — not even a typical one. Add them as named rows with your own numbers and total your sheet as materials from CSI plus your own costs.

There is also a specification blank worth naming, because it is the one readers most expect this page to fill. No CSI product page publishes a glass thickness in millimetres, a drop-test rating or a breakage rate, and neither does this page. Black Glass Jar with Black Lid (150 gram) is described on its page as thick-walled and publishes its dimensions and an 85°C hot-pour limit; Yankee Glass Jar 130 ML publishes neither a thickness nor a capacity. If glass specification is the deciding factor for you, ask on WhatsApp rather than inferring it from price.

One last honest note on the pack ladders behind these figures, since a costing built on the wrong pack is wrong before breakage is considered. Luxury Soy Wax CSI 464 is ₹520.00 a kilogram in the 500 g pack and ₹507.40 from 1 kg upward, flat across the 1 kg, 5 kg and 10 kg packs. Fresh Strawberries Fragrance Oil runs ₹4.25 a gram at 50 gm, ₹3.78 at 100 gm and ₹3.54 at both 500 gm and 1 kg. Black Glass Jar with Black Lid (150 gram) is ₹107.00 a piece in both the pack of 10 and the pack of 20. Those are the published rates in September 2026 — check the pack you are actually buying rather than assuming the largest is cheapest.

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