How this calculator works
Slate coasters are the classic underpriced laser product. The blanks are cheap, so the finished set feels like it should be cheap too — but a set of four carries four blanks, four sets of feet, four lots of oiling and cleaning, and a laser run that only holds so many at a time.
This calculator prices by the set. Enter your per-coaster costs and how many go in a set, and it handles the multiplication, the laser batching, and the breakage allowance.
The formula
- Materials = sets × coasters per set × per-coaster cost ÷ (1 − waste %)
- Per-coaster labour = minutes × coasters per set, then × sets; design and setup charged once
- Laser runs = ⌈ (sets × coasters per set) ÷ coasters per run ⌉
- Breakage allowance = (materials + laser + hands-on labour) ÷ (1 − breakage %) − those costs
- Price per set = (cost per set + fixed fee ÷ sets) ÷ (1 − target margin − fee %)
What to watch for
- Everything is priced per set because that is how coasters sell, but the costs are per coaster. Enter your per-coaster figures and the set size, and the multiplication is handled for you.
- Laser runs are computed on total coasters, not sets. A dozen sets of four is forty-eight coasters, which at six per run is eight runs — not two.
- Finishing is the step most often forgotten. Cleaning, oiling and applying feet at 1.6 minutes a coaster is well over six minutes on a set of four, which at a finishing rate is real money.
- Slate chips and cracks, and it engraves inconsistently across natural variation in the stone. A breakage allowance of zero is optimistic on any real production run.
- Design and setup are charged once per job, so a single pair carries the whole of both. Use a minimum order to stop one-off sets losing money.
Common mistakes
- Pricing a set from the blank cost, when the blanks are often under a fifth of the true cost.
- Computing laser runs from the number of sets rather than the number of coasters.
- Leaving out cleaning, oiling and applying feet, which is the largest labour line on a set.
- Setting breakage to zero on a natural stone product.
- Forgetting that a set needs one lot of packaging but four lots of everything else.
Frequently asked questions
How much should I charge for a set of engraved slate coasters?
Price by the set from per-coaster costs. A set of four carries four blanks, four sets of feet, four lots of cleaning and oiling, a share of the laser runs, and one lot of packaging. Once design, setup, breakage and fees are counted, the honest price is usually several times what the blanks alone suggest — enter your own figures, since blank cost varies a lot by supplier and size.
How many coasters should I put on the laser bed at once?
As many as fit with enough jig spacing to stay aligned, because the run is charged whole regardless of how full the bed is. Increasing coasters per run is one of the few changes that genuinely lowers your cost per set, since it cuts the number of cycles the whole order needs.
What breakage rate is realistic for slate?
Slate is a natural material that chips at the edges, occasionally cracks under heat, and varies in how evenly it engraves. Many makers see 3–8% across a production run. If you have not measured yours, 5% is a reasonable starting point, and it should include pieces you reject on appearance, not only ones that physically break.
Should I charge less per set for larger orders?
A little, but less than you might think. Only design and setup spread across the order — blanks, feet, oiling, laser runs and packaging all scale with quantity. The calculator shows recalculated prices at double and five times your quantity so you can see the real saving rather than guessing at a discount.
How do I price single coasters for wedding favours?
Set coasters per set to one and the quantity to the number of favours. Each is individually packed and often individually personalised, so packaging stays per unit while design time depends on whether every piece carries a different name — if it does, the setup does not spread and the per-unit price stays high.