Is shipping on supplies part of your material cost?

The short answer

• Yes. Shipping you pay to get materials in is part of what they cost.
• Spread one charge across the order by each line's share of the price, then divide by quantity.
• On a $100 order with $18 shipping, that is 20 cents on every bar of a 50-bar batch.
• Shipping to your customer, and the mailer, are not material cost.

Yes. If you paid $18 to have a box of oils delivered, those oils cost you $18 more than the invoice says, and every bar you make from them carries a slice of it. Most makers know this, and most spreadsheets skip it, because the shipping sits on its own line at the bottom of the invoice and there is no obvious cell to put it in. The fix is to spread it across the things in the box, and the arithmetic takes two minutes.

Why does shipping on supplies count as material cost?

Because a material costs what it took to get it to your bench, not what the supplier printed on the line. A 7 lb pail of coconut oil with $21.00 on the invoice and $3.78 of freight behind it cost you $24.78, and $21.00 is not a price you could have bought it for. Accountants call the full figure the landed cost. It is the only number that should feed your cost per bar.

The IRS's own definition of inventory cost, in Publication 538 under Valuing Inventory (checked 2026-09-18), reads: "the invoice price minus appropriate discounts plus transportation or other charges incurred in acquiring the goods." That is a definition of the word cost, not tax advice, and how anything is reported on a return is a question for your accountant. For costing, though, it settles the question, because the freight belongs to the goods.

It does not cover two things. Shipping an order to your customer is a cost of that sale, not of the material, and it belongs on the order. The mailer, tape and paper you send it in are the same: a cost of selling, not of making. The box a bar is sold in is different again. That is packaging, and it gets its own material line.

How do you spread one shipping charge across several materials?

In proportion to what each line cost. Work out each line's share of the subtotal, give it the same share of the shipping, add that to the line, and divide by the quantity you received.

One order, three lines, one supplier:

Line	Quantity	Invoice	Share of subtotal
Olive oil, two 7 lb pails	14 lb	$56.00	56%
Coconut oil, one 7 lb pail	7 lb	$21.00	21%
Fragrance oil, 16 oz	1 lb	$23.00	23%
Subtotal		$100.00	100%
Shipping		$18.00

Those three landed figures are what go into your materials list. Every recipe that uses olive oil now costs it at $4.72 a pound, and it stays there until the next order arrives at a different landed price and the two get averaged together.

Shares are rounded to the cent, and on an awkward order they can come to a cent over or under the shipping; when they do, put the odd cent on the largest line. Nothing gets lost and nothing gets counted twice: the $18.00 you paid is the $18.00 that ends up in the oils.

What does that do to your cost per bar?

It puts every cent of the freight into the bars, spread over however many bars the oils will make. Take a batch that uses 8 lb of the olive oil, 4 lb of the coconut oil and 8 oz of the fragrance, and cuts 50 bars. Lye, water, colour and the label come from other orders and do not change here; this is the three lines from this box.

	At invoice price	At landed price
Olive oil, 8 lb	8 × $4.00 = $32.00	8 × $4.72 = $37.76
Coconut oil, 4 lb	4 × $3.00 = $12.00	4 × $3.54 = $14.16
Fragrance oil, 0.5 lb	0.5 × $23.00 = $11.50	0.5 × $27.14 = $13.57
These three lines, per batch	$55.50	$65.49
Per bar, 50 bars	$55.50 ÷ 50 = $1.11	$65.49 ÷ 50 = $1.31

That is twenty cents a bar, or 18% on these three ingredients, from a shipping line that never made it into the spreadsheet. If you priced those bars from $1.11, the 20 cents comes out of your margin on every one of them, and it keeps coming out for as long as you use these oils.

The batch picked up $9.99 of the $18.00, not all of it, because it used four-sevenths of the oils and half of the fragrance. The rest is still in the pails and comes out in the next batches. The freight follows the material, so it reaches the bars in the same proportion the material does.

When should you split shipping by weight instead of by price?

When the box is heavy and cheap in one place and light and expensive in another. Carriers charge by weight and size, not by what you paid, so a pound of olive oil and a pound of fragrance oil cost the same to move even though one costs nearly six times the other to buy. Splitting by price gives the fragrance 23% of the freight for 4.5% of the weight.

Splitting by weight gives every pound in the box the same slice. Same order, 22 lb in total:

On this order the two methods differ by 10 and 28 cents a pound on the two oils and by $3.32 a pound on the fragrance, and the batch above moves by 26 cents in total, because the box was mostly oil. Where it matters is an order like 20 lb of wax and one $90 bottle of essential oil. By price the wax carries almost none of the freight it caused, so every candle made from it looks cheaper than it is, and the essential oil looks dearer.

Pick one method and keep it. By price is the default because it needs nothing but the invoice; by weight is better when the weights are on the invoice and the box is lopsided. Switching from order to order makes the same oil cost a different amount for no reason you can explain later.

Why does a small order make every bar cost more?

Because the shipping is close to fixed and the subtotal is not. $18.00 on a $100.00 order is 18% on top of everything in the box. Say the same supplier ships twice the order, $200.00 of the same three oils, for $24.00. That is 12%, and every landed price falls.

	$100 order, $18 shipping	$200 order, $24 shipping
Olive oil, per lb	$4.72	$4.48
Coconut oil, per lb	$3.54	$3.36
Fragrance oil, per lb	$27.14	$25.76
The same 50-bar batch, three lines	$65.49	$62.16
Per bar	$1.31	$1.24

That is seven cents a bar from order size alone, on the same recipe from the same supplier. Freight explains much of why a bar costs one maker more than another to make; the price of olive oil is the same for everyone. The table also tells you what a bigger order buys. The larger one puts $106 more on the shelf ($224.00 against $118.00), and in return every bar is seven cents cheaper for as long as the oil lasts.

Do sales tax and discounts work the same way?

Yes, in the same step. Sales tax charged on the order is one more cost of getting the goods, and it spreads across the lines exactly like the shipping. A discount on the order is the same thing with the sign flipped: spread it the same way and subtract it. The IRS definition quoted above has both in one sentence, invoice price minus discounts plus transportation, and that is the whole formula:

landed cost of a line = invoice price + the line's share of (shipping + tax − discount)

There is one caution on discounts. A line-level discount, 10% off olive oil this month, belongs to that line only. Spread only what was taken off the order as a whole. And if a large flat discount on a small order would push a line's landed cost below zero, the discount is really a rebate; book it as one rather than spreading it.

Trackost does this on every purchase order. You enter the lines, the shipping, the tax and any order-level discount, choose whether to spread them by value, quantity or weight, and it shows the share and the landed figure on every line before you save, reconciled to the cent. When the goods arrive, each line's landed cost runs through the material's weighted-average unit cost, so the next batch costs its olive oil at what the olive oil actually cost to get here.

Questions

Is shipping to my customer part of my material cost?

No. Postage on an outgoing order is a cost of that sale and belongs on the order, not on the materials. Only the freight you pay to bring supplies in is part of what those supplies cost.

Are shipping boxes and mailers part of my material cost?

Not unless they are part of the product. The box a bar is sold in is packaging and gets its own material line. The mailer, tape and filler you post it in are a cost of selling, and they stay out of the cost per bar.

Can I just record the shipping as a separate expense instead?

You can book it that way, but then your cost per bar is understated by the whole freight charge, and every price set from it is too low. Spread it into the materials for costing. How it is reported on a tax return is a question for your accountant.

What if I split the shipping equally across the items?

It charges every line the same amount whatever it cost or weighed. On the order above, $6.00 each takes fragrance oil from $23.00 to $29.00 a pound but olive oil only from $4.00 to $4.43. Any recipe heavy in one and light in the other gets the wrong number.

What if shipping was free?

Then there is nothing to spread and the invoice price is the landed price. The cost of reaching a free-shipping threshold is the extra stock sitting on your shelf, which is a cash question, not a cost-per-bar one.