InfillGuide
How Much to Charge for 3D Prints
Your slicer tells you 42 grams and 3 hours 20 minutes. It does not tell you what to charge. Here is the whole method, with the arithmetic written out.
Step one: count every line, not just the plastic
Most sellers price a print off the filament alone, which is usually the smallest number on the page. A print costs you seven things, and Infill charges each of them separately so you can see which one is actually driving the price.
- Material. Grams off the slicer, at the price of the filament you used, plus that filament's waste allowance.
- Purge and color changes. The material flushed at every filament change. Its own line, not a percentage.
- Electricity. Average watts times print hours times your tariff.
- Machine. Purchase price divided by expected lifetime hours, plus maintenance per hour.
- Labor. Your hands-on time at your hourly rate. Modelling, plating, removal, cleanup.
- Post-processing. Sanding, painting, inserts, glue. Whatever the part needs after it comes off the bed.
- Packaging and shipping. Per order, never multiplied by the failure rate, because a failed print is reprinted and not re-shipped.
Failed prints then sit on top of all of that. They are not an eighth cost so much as a multiplier on the seven.
Step two: allow for the prints that fail
If a fifth of your prints fail, you do not add 20 percent. You rerun the job until one good part comes off the bed, so on average you pay for 1 divided by 0.8 prints, which is 1.25. The flat surcharge version undercharges you every time, and it undercharges you more the worse your failure rate is.
| Failure rate | Flat surcharge | Expected reruns | You lose |
|---|---|---|---|
| 5 percent | 10.50 | 10.53 | 0.03 |
| 10 percent | 11.00 | 11.11 | 0.11 |
| 20 percent | 12.00 | 12.50 | 0.50 |
| 30 percent | 13.00 | 14.29 | 1.29 |
Infill carries a failure rate per printer, because a well fed enclosed machine and a five year old bed slinger do not fail at the same rate.
Step three: margin, not markup
This is the single most common mistake in print pricing, and it is worth being pedantic about. A margin is a share of the selling price. A markup is a share of your cost. They are only equal at zero.
| Percentage | As markup | As margin |
|---|---|---|
| 20 percent | 14.40 | 15.00 |
| 30 percent | 15.60 | 17.14 |
| 50 percent | 18.00 | 24.00 |
| 60 percent | 19.20 | 30.00 |
A calculator that multiplies your cost by one plus the margin and then calls the result a margin is quoting a third under at 50 percent. Infill keeps the two modes apart, labels which one is active, and converts between them when a customer preset needs to compare like with like.
Step four: charge this person, not the average person
The hard question is rarely what a print costs. It is what to charge this person. Nobody bills a flatmate what they bill a shop. Infill puts four situations behind one row of buttons, and each moves your hourly rate and your margin together.
| Preset | Hourly rate | Margin | What it means |
|---|---|---|---|
| Friend | 0 percent | 0 percent | At cost. Your time is a gift. |
| Known | 50 percent | 15 percent | Half your hourly rate, small margin. |
| Stranger | 100 percent | Your setting | Full rate and your normal margin. |
| Business | 125 percent | 60 percent floor | Full rate plus a commercial premium. |
The business figure is a floor and not a fixed value. If you already work at 70 percent, a trade buyer is not quietly quoted less than a stranger.
Let the app do the four steps
Infill carries the cost lines, the failure allowance, the margin and markup distinction and the customer presets, so a quote takes two numbers off the slicer.
Free on the App Store. iOS 17.0 or later, iPhone and iPad. No account, no advertising, no tracking.
The whole thing, worked out once
A 42 gram PLA print, 3 hours 20 minutes on a Bambu Lab P1S, 10 minutes of your hands, electricity at 0.30 per kWh and your rate at 20.00 per hour. These are Infill's own default profiles.
| Line | How it is worked out | Amount |
|---|---|---|
| Labor | 10 min at 20.00 per hour | 3.34 |
| Material | 0.042 kg at 22.00 per kg, plus 2 percent waste | 0.94 |
| Machine | 699.00 over 6000 h, plus 0.03 per h maintenance | 0.49 |
| Failed prints | 4 percent failure rate on the P1S profile | 0.20 |
| Electricity | 130 W for 3 h 20 m at 0.30 per kWh | 0.13 |
| Total cost | 5.10 | |
| Charge at 50 percent margin | 5.10 divided by 0.5 | 10.20 |
Notice what is doing the work. Your time is two thirds of the cost, and the plastic everybody prices on is under a fifth. That ratio is why filament-only pricing lands so far under, and it is why the labor line is the first thing to argue about.
Labor reads 3.34 rather than 3.33 because the rounding residue is pushed onto the largest line, so the listed items add up to the total exactly. A breakdown whose rows do not sum to their own headline is the worst thing a pricing app can put on screen.
Guides
Go deeper on one line
- Filament cost calculator: price per gram
Spool price to price per gram, waste allowance, and what a 42 g print actually costs in plastic.
- 3D printer electricity cost per hour
Average watts for twelve popular printers, and why power is almost never your biggest line.
- G-code cost calculator
What PrusaSlicer, Bambu Studio, OrcaSlicer and Cura write into a file, and what Infill reads back out.
- AMS purge waste cost
Multi-color prints throw filament away at every change. Here is how to put a number on it.
Quote your next print properly
Free on the App Store, with no advertising and nothing to sign up for.
Free on the App Store. iOS 17.0 or later, iPhone and iPad. No account, no advertising, no tracking.