Most advice on print costing tells you what to include. Fewer posts show the sum. So here is one print, costed on paper, with every input labelled as something you can measure or something you are guessing. All numbers are illustrative and round. Swap in your own.
The print
A desk organiser, one part, one colour, printed alone on one printer.
- Slicer says 180 g of filament, 6 hours of print time.
- Filament spool: 1 kg for 20 (any currency, we just use "units").
- Printer bought for 600, expected to print for about 3,000 hours before you replace it.
- Printer draws an average of 120 W while printing.
- Electricity: 0.30 per kWh.
- Your time: 10 minutes in total (remove, clean, pack), at 20 per hour.
- Packaging: 1.00.
Step 1: filament
180 g at 20 per kg is 3.60. This is the easy line, and the one people stop at.
Two things make it wrong. Purge and waste (colour changes, prime lines, supports you throw away) are not in the part weight. And the slicer's estimate is not the spool's reality. Weigh a few finished parts against the estimate before trusting it. If your slices run 5% light, add that.
Say purge adds 10 g here. Then 190 g, so 3.80.
Step 2: machine time
This is the line most often left out, because no invoice arrives for it.
Purchase price divided by lifetime hours: 600 / 3,000 = 0.20 per hour. Then add maintenance and repairs. Say nozzles, belts and a hotend swap come to 150 over that life: another 0.05 per hour. Then overhead (rent, internet, software, a share of your own admin), say 0.25 per hour per printer.
Total about 0.50 per hour. Over 6 hours: 3.00.
What is a guess here: the lifetime hours. Nobody knows. Pick a figure, write it down, and revisit it after a year of real repair records.
Step 3: electricity
120 W for 6 hours is 0.72 kWh. At 0.30 per kWh, that is 0.22.
Small, but not zero, and it grows with enclosures, heated beds at high temperature and big printers. The watt figure is the one to measure: a plug-in power meter on one printer for one full print tells you more than any spec sheet. Average draw is far below peak draw, so do not use the label figure.
Step 4: labour
Ten minutes at 20 per hour is 3.33.
Count the touchpoints separately, because they differ by product: starting the print, removing it, support removal, sanding or finishing, quality check, packing. Time them once with a phone stopwatch on a normal day, not your fastest. Nobody's real average matches their best run.
Step 5: packaging
1.00. Include the box, filler, tape and label stock, not just the box. Shipping and marketplace or payment fees come after this and depend on the channel, so they are left out here.
Step 6: failures
Failures are the line that turns a comfortable margin into a thin one.
Suppose this part fails 1 time in 10. Each failure wastes roughly a full set of material, machine time and electricity, plus some labour to clear the bed. Simple method:
- Cost of one attempt (steps 1 to 3): 3.80 + 3.00 + 0.22 = 7.02.
- Failure rate: 10%.
- Surcharge: 7.02 × 0.10 / 0.90 ≈ 0.78 per good part.
The division by 0.90 matters. To get 9 good parts out of 10 attempts you need to spread the loss of one failed attempt over 9, not 10.
The failure rate is the shakiest input. Do not guess it from memory. Keep a tally per part for a month: attempts and good parts. Early-layer failures on a new part and late failures on a long print cost very different amounts, so a rough average of a part's history is better than a global one.
The total
| Line | Cost |
|---|---|
| Filament including purge | 3.80 |
| Machine time | 3.00 |
| Electricity | 0.22 |
| Labour | 3.33 |
| Packaging | 1.00 |
| Failure surcharge | 0.78 |
| Total before shipping and fees | 12.13 |
Filament is about 31% of that. If you had priced at 3x filament (10.80), you would be under cost before a single fee.
What goes wrong in practice
- Using the slicer's time as machine time. Real jobs include heat-up, bed levelling and the wait before someone clears the plate. A bed that sits full overnight is still occupied.
- Costing labour at zero because you do it yourself. Then you cannot tell whether hiring help would pay.
- One global failure rate. Tall, thin or unsupported parts fail more. Cost per part.
- Never updating the inputs. Filament prices, power tariffs and repair bills drift. Review them every quarter.
- Mixing measured and guessed numbers without marking them. When the total looks off, you cannot tell which line to question.
An order to do this in
- Time one normal day of labour and write the minutes per step.
- Meter one printer for a full print to get average watts.
- Weigh five finished parts against their slicer estimates.
- Start a failure tally per part.
- Set a lifetime-hours guess for each printer and mark it as a guess.
- Build the sum above in a spreadsheet, one row per product.
After a month you will have a cost per product you can defend, and a short list of guesses to tighten.
How PrintSol helps
PrintSol works out the cost of each order and product from filament, purge, machine time, electricity, labour, packaging, shipping and fees. It adds a failure surcharge from each part's measured failure rate, and marks each cost line as measured or estimated. There is a Free plan to try it on your own numbers: pricing.
