You didn’t notice the moment your rotary blade went dull. You just noticed the cut started dragging, the edge got fuzzy, and one afternoon you swapped in a fresh blade from the pack in the drawer. The old one went in the trash. You never thought about it again — and you definitely never charged anybody for it.
That’s the problem. The blade wasn’t free. Neither was the sandpaper you burned through last month, the drill bit that stopped biting, the needles that snapped, or the polishing wheel that’s now half the size it started. Every one of those got used up making the things you sold. But because you bought them in a bulk pack back in spring, and they die slowly, they never line up with a single sale. So they quietly fall out of your price.
This is not the same as your machine wearing out
People hear "tool cost" and think depreciation — the sewing machine, the laser, the kiln slowly earning back what you paid for it. That’s a real thing, and it deserves its own line. But consumables are different, and simpler. Depreciation is the machine losing value over years. Consumables are the stuff that literally gets consumed — used up and thrown away — batch after batch: blades, bits, sanding discs, glue sticks, engraving tips, thread, needles, cutting mats, buffing wheels.
The reason they slip through is that they’re cheap one at a time and you buy them months apart. A $12 pack of five blades doesn’t feel like a cost you assign to a wallet. Your brain files it under "supplies I already have." But you didn’t already have it — you bought it, and it’s disappearing into your products a few cents at a time.
The whole formula is one line
Here’s all the math there is:
Consumable cost per item = what the consumable costs ÷ how many items it survives before you toss it.
That’s it. If a $12 five-blade pack means $2.40 a blade, and one blade cuts cleanly through about 20 wallets before it starts dragging, that’s 12 cents of blade in every wallet. Do the same for each consumable and add them up.
A worked example, because the pennies add up faster than you think
Take a leatherworker making a batch of card wallets. Walk the consumables:
- Rotary blade: $2.40 ÷ 20 wallets = $0.12
- Sandpaper / burnishing: a $9 assortment that edges roughly 60 wallets = $0.15
- Needles and thread wear: call it $0.10 per wallet in snapped needles and used thread beyond the thread you already count as material
- Edge paint applicator / small consumables: $0.08
That’s $0.45 per wallet in pure consumable wear — before leather, before hardware, before your time. It looks like nothing. Now run your Q4 numbers: 300 wallets between October and December is $135 of tool wear you never charged for. That’s not pennies anymore. That’s a full restock, or a chunk of your holiday ad budget, evaporating out of a line you didn’t know you had.
And it’s worse for anyone running a machine. Makerspaces bill laser time at around $0.50 a minute — a rate that exists precisely because the tube, lens, and cutting surfaces wear with every job. A refill pack of a laser cutting mat plus five fine blades runs about $25.99. If a four-minute engrave costs $2.00 in metered runtime and consumables, and you sell that coaster for $12, you just gave away 17% of the price by calling the machine "free" because you own it. The pros meter it. The only person treating it as $0 is you.
Why fall is the worst time to keep ignoring it
Consumables wear at the speed of your volume. All year you might stretch a blade for months — but the holiday run compresses a season of cutting into a few weeks. You’ll burn through blades, discs, and glue sticks in October that you’d normally make last until spring. Your outlay on supplies lands now, in September and October, while the revenue doesn’t arrive until November and December. So every unpriced consumable widens the gap at exactly the moment your cash is tightest. Getting this line right before the batch is the difference between a holiday season that funds next year and one that just refills the drawer.
"It’s a few cents — who’s going to track every blade?"
Nobody is asking you to track every blade. That’s the objection, and it’s fair — and the answer is that you don’t have to. You estimate it once. Price ÷ items survived, per consumable, guessed honestly. Add the handful of them into one small "tool wear" figure. Save it. It rides along on every product you price from then on, because unlike the price of leather or a zipper, this number doesn’t change order to order. It’s the easiest cost line to capture in the whole business — you do the thinking one time and it protects your margin forever.
That’s exactly the kind of quiet, repeatable cost a costing tool is built to carry for you. In CrafterBy you set a consumable or wear line once and it folds into the true cost of every item that uses it, so your price already includes the blade and the sandpaper without you doing mental math on a sticky note. You’ve been paying for these tools out of your own pocket all along. This is just charging what your work already costs to make — and heading into your biggest season with the real number, not the flattering one.
Stop leaving the blade off the invoice. Run one product through the free calculator with your tool wear included, and see what your honest price actually looks like.
