How to charge for design time in 3D printing
Design is the only cost that does not multiply by the parts you print. Here is where it goes in the calculator and what happens when you put it in the wrong place.
Written by Álvaro Melgar Merenciano·
You spend three hours modelling a part. Then you print it: 5.11 € of cost, you list it at 7.66 € and you keep 2.55 € of profit. You sell ten. You have made 25.55 € for a job that took three hours of design plus the time to print and pack ten parts.
If those three hours are worth the same as the rest of your time, 12.00 € an hour, you have just worked below cost and it does not show up in any account. Design is the expense that most often stays out of the price, and the only one that behaves differently from all the others.
Design is not labour
Material goes up if you print more parts. Electricity goes up. Machine depreciation goes up. The minutes spent removing the part and cleaning the bed go up. All of that is cost per unit: every new part pays it again in full.
Design does not. You model once and that is it. Part number one hundred comes out of the same file as the first, without a single extra minute of CAD. It is a fixed cost, and fixed costs are not added to the price: they are spread across the units you are going to sell.
That distinction sounds like it belongs in an accounting manual, but it has a very concrete consequence: the working minutes field in the calculator is meant for what you do on each part. Putting your design hours in there is telling the calculator you are going to model the part again, from scratch, every time somebody buys one.
Twenty-six minutes
Before spreading anything, it helps to see the size of the problem. This site's reference part — 60 grams of PLA, 5 h 30 of printing — costs 5.11 € to produce, counting material, electricity, machine, the 10% failure rate and a quarter of an hour of your own handling.
At 12.00 € an hour, 5.11 € is twenty-five and a half minutes of your time. Which means: the moment you go past twenty-six minutes at the computer, designing that part has already cost you more than printing the whole thing.
And twenty-six minutes is not a design, it is a tweak. This is what each stretch of time costs you, against what the part costs:
| Time spent designing | What your time is worth | Against the cost of the part |
|---|---|---|
| 10 minutes | 2.00 € | 39% |
| 20 minutes | 4.00 € | 78% |
| 30 minutes | 6.00 € | 117% |
| 1 hour | 12.00 € | 235% |
| 3 hours | 36.00 € | 705% |
Three hours of design are worth seven times what printing the part costs. Which is why it matters where you put it.
The same design, spread out
The right calculation is a division: your design hours divided by the units you are actually going to sell. With three hours at 12.00 € — 36.00 € — and the 5.11 € part, it comes out like this:
| Units you sell | Design per part | Real cost | Price with markup |
|---|---|---|---|
| 1 | 36.00 € | 41.11 € | 61.66 € |
| 5 | 7.20 € | 12.31 € | 18.46 € |
| 10 | 3.60 € | 8.71 € | 13.06 € |
| 20 | 1.80 € | 6.91 € | 10.36 € |
| 50 | 0.72 € | 5.83 € | 8.74 € |
| 100 | 0.36 € | 5.47 € | 8.20 € |
| 200 | 0.18 € | 5.29 € | 7.93 € |
The same part, the same design, and the price runs from 61.66 € to 7.93 €. The only thing that changes is how many people are going to buy it.
There is one figure worth keeping in mind: at thirty units the spread design lands exactly on 1.20 €, which is exactly what the plastic in the part costs. Below that run your CAD work weighs more than the material; above it, less.
And from there comes the practical rule: design is not spread across the parts you would like to sell, but across the ones you are going to sell. If you put 200 in the division and then sell 12, nobody pays the difference: you do.
What happens if you put it in the labour field
This is the actual mistake, and it is an easy one to make because the field looks like the logical place. If you type 180 minutes into working minutes, the calculator does exactly what you asked: it charges three hours of your time on every single unit.
| Where the 3 hours go | Working minutes | Cost per part | Price per part |
|---|---|---|---|
| Spread across the 20 | 24 | 6.91 € | 10.36 € |
| In full, on every part | 195 | 41.11 € | 61.66 € |
| Difference | — | 34.20 € | 51.30 € |
On a run of twenty parts that is 1,026.00 € of difference in the total price. That is not a detail: that is the difference between selling and nobody buying.
The right way to use the field is to turn the spread design into minutes. Three hours across twenty parts are nine minutes per part. Add them to the fifteen minutes of handling and type 24. You can watch it work: the pricing calculator with the design already spread across 20 parts gives you 10.36 €.
How many parts it takes for a design to pay for itself
There is another way of looking at it that is even more useful, especially before you sit down to model: instead of spreading the design, ask how many sales it takes to get it back.
At that part's catalogue price, 7.66 €, the profit is 2.55 € per unit. Dividing the design by that profit gives the number of parts that exist only to pay for the hours you spent designing:
| Design time | What it is worth | Parts just to pay for it |
|---|---|---|
| 30 minutes | 6.00 € | 3 |
| 1 hour | 12.00 € | 5 |
| 2 hours | 24.00 € | 10 |
| 3 hours | 36.00 € | 15 |
| 6 hours | 72.00 € | 29 |
An afternoon of six hours modelling needs twenty-nine sales before it returns the first euro. If you sell three parts a month, that is almost a year of work to cover one afternoon.
This does not mean designing is not worth it. It means that before you sit down it is worth having an honest idea of how many you will sell, because that number decides whether the design is an investment or a gift.
“I will design it for free if you buy some”
It is the offer almost everyone uses to close their first repeat order: I will not charge you for the design, you buy a few units. It sounds like an investment and sometimes it is, but it is worth knowing from where.
| Parts in the order | Profit | Design given away | You keep |
|---|---|---|---|
| 5 | 12.77 € | −36.00 € | −23.23 € |
| 10 | 25.55 € | −36.00 € | −10.45 € |
| 15 | 38.32 € | −36.00 € | 2.32 € |
| 20 | 51.10 € | −36.00 € | 15.10 € |
An order of ten parts with the design given away leaves you 10.45 € below zero. You have worked three hours, printed ten parts, packed ten orders, and put money in on top.
The point where it starts to pay off is fifteen parts, and what you earn there is 2.32 €. Below that number, giving the design away is not a commercial investment: it is paying for the privilege of working.
The one-off commission, line by line
The most common case of all and the worst charged: somebody asks you for a part that does not exist. Nobody else is going to buy it, so the design is spread across one unit.
Three hours of modelling, the same 60-gram, 5 h 30 part:
| Item | Amount |
|---|---|
| Producing the part (material, electricity, machine, failures and handling) | 5.11 € |
| Design: 3 h at 12.00 €/h, spread across 1 part | 36.00 € |
| Real cost | 41.11 € |
| 50% markup | 20.55 € |
| Price | 61.66 € |
Check the number yourself: the calculator with the three design hours loaded onto a single part. That is 195 working minutes: the 180 of design plus the 15 of handling.
Now what actually happens. Almost nobody charges 61.66 € for a part like that, because the customer compares it with what a similar object costs in a shop. This is what you keep depending on what you dare to ask for:
- 20.00 € — you lose 21.11 €.
- 30.00 € — you lose 11.11 €.
- 40.00 € — you lose 1.11 €. At 40.00 € you still do not cover the cost.
- 61.66 € — you cover the cost and earn 20.55 €.
The price looking high does not mean it is badly calculated. It means custom design is expensive, because those are your hours and they are not shared with anybody. The honest way out is not to drop the price: it is to charge the design separately, as its own line on the quote, and keep the file yourself so you can sell it to more people later. That is where it gets spread.
Revisions are design all over again
“Could you raise the rim a little?” Half an hour. “And could the hole be a millimetre bigger?” Another half hour, plus printing it again.
At 12.00 € an hour, every half hour of tweaking is 6.00 €. Three revisions are 18.00 €, which on the one-off commission takes the cost from 41.11 € to 59.11 €. And that is before the plastic of the intermediate versions that end up in the bin, which the failures guide already showed is not the expensive part, but it adds up.
What works is saying it beforehand, not afterwards: two revisions included, the third is charged. That is not being unfriendly, it is what any workshop does. A customer who is told the limit from the start sends all the changes at once; one who is not tells you about them one at a time over a fortnight.
If the model is not yours
There is an obvious way out of all of the above: do not design. Download the model from a repository like Printables or Thingiverse and just print. Your design time becomes zero and the whole table above disappears.
With two warnings worth reading first.
The first is legal. A file being free does not mean you can sell what you print with it. Many models are published under Creative Commons licences that include the NC clause, for non commercial: you can print it for yourself, you cannot sell it. The licence is always on the model's page and checking it takes ten seconds. Some authors sell a separate commercial licence, and that amount is a fixed cost of yours: it spreads across the units exactly like design does.
The second is that zero is not zero. Even when the model is free, it still has to be prepared: scaled, oriented, supported, sliced and test-printed once. That rarely comes in under half an hour, which is 6.00 €. It is far less than designing, but it is not nothing, and it is a fixed cost in exactly the same way: it spreads across the parts you are going to sell.
What hourly rate to set
Everything above rests on one number only you can decide: what your hour is worth. The calculator comes with 12.00 € by default because it is a cautious figure for somebody starting out who does not live off this, not because it is the right one. This is what changes depending on what you set:
| Your hour | 3 h of design | Per part, across 20 units |
|---|---|---|
| 8.00 €/h | 24.00 € | 1.20 € |
| 12.00 €/h | 36.00 € | 1.80 € |
| 18.00 €/h | 54.00 € | 2.70 € |
| 25.00 €/h | 75.00 € | 3.75 € |
Look at what happens in the last column: going from 8.00 to 25.00 € an hour, more than triple, only raises the cost of each part by 2.55 €. On a reasonable run, paying yourself properly barely shows in the final price. Where it does show is on the one-off commission, and that is why custom work is charged differently.
I am not going to give you an industry average, because any figure I gave you would be made up. The serious way to decide it is the other way round: look at what you are paid per hour at work, or at what it would cost you to commission that part from a designer in your city, and start there.
The mistakes that eat the number
Counting only CAD time. Design starts earlier: talking to the customer, understanding what they want, taking measurements, looking for references. If you modelled for three hours but spent four on it, the cost is four.
Spreading across imaginary units. It is the most expensive trap of them all, because it happens without meaning to and out of optimism. Dividing by 100 when you are going to sell 12 does not lower your cost: it hides it.
Redoing the spread and not touching the price. If the first twenty sold well and you are now making another fifty, the design on those fifty is already paid for. You can drop the price, or keep it and earn 1.80 € more per part, but that is a decision, not an oversight.
Forgetting that the file stays with you. A design you have been paid for once and can keep selling is worth more than the hours it took. If on a custom commission you hand over the file exclusively, that is charged separately, because you are giving up ever spreading it again.
Putting it in the labour field. We have already seen it: on twenty parts that is 1,026.00 € of difference.
Do it with your own figures
The full calculation is two steps, and both happen in the pricing calculator.
One. Divide your design hours by the units you are actually going to sell and turn it into minutes. Three hours across twenty parts is 180 minutes divided by 20, that is 9 minutes per part.
Two. Add those minutes to the ones you really spend on each part — removing it, cleaning, finishing, packing — and type the total into working minutes. Nine plus fifteen is twenty-four.
If the commission is for a single part, there is no spreading: you put the design hours in whole and that is that. And if you want to see what the bare part costs first, with no design and no markup, it is in the cost calculator.
One last thing, and it is the one that changes the sums most for anybody who sells: if you sell on a marketplace, the price that comes out of here is not what reaches you. Fees take their share and VAT takes its own, and that is covered in the guides on Etsy fees and VAT on selling 3D prints.
Want the exact number for your own case? 3D printing cost calculator does the full sum with your filament, your electricity tariff and your printer, and leaves the quote ready to copy.
Frequently asked questions
Is design time charged on every part or just once?
Just once. Design is a fixed cost: you model once and part number one hundred comes out of the same file as the first. It is spread across the units you are going to sell, not added to each one.
That is why 36.00 € of design is 36.00 € per part if you sell one, and 0.18 € per part if you sell 200.
Where do I put design time in the calculator?
In the working minutes field, but spread. Divide your design minutes by the units you are going to sell and add the result to the minutes you spend on each part.
Three hours across twenty parts is 9 minutes per part. With the 15 of handling, you type 24.
What happens if I put the whole design time into labour?
The calculator charges you the full design on every single unit. The part goes from 10.36 € to 61.66 €, and on a run of twenty that is 1,026.00 € of difference.
It is only correct when you really are going to sell one single part, as in a custom commission.
How many parts do I have to sell to pay for three hours of design?
Fifteen. At 2.55 € of profit per part at the catalogue price, it takes 15 sales to recover the 36.00 € those three hours are worth.
An afternoon of six hours needs 29 sales before it returns the first euro of profit.
Is it a good idea to design for free to win the order?
Only from fifteen parts up. On an order of ten you end up 10.45 € below zero: you have worked three hours, printed ten parts and put money in on top.
With fifteen parts you earn 2.32 € and with twenty, 15.10 €. Below fifteen, giving the design away is paying for the privilege of working.
How much should I charge per hour of design?
The calculator comes with 12.00 €/h by default, which is a cautious figure for somebody starting out. The sensible thing is to start from what you are paid per hour at work, or from what commissioning that part outside would cost you.
On normal runs the rate barely shows: going from 8.00 to 25.00 €/h raises the cost of each part by only 2.55 € on a run of twenty.
What if I downloaded the model from the internet?
Then your design time is zero, but check the licence: many free models carry the NC clause, which lets you print them for your own use but not sell what you print.
And preparing it is not free either: scaling, orienting, supporting, slicing and printing the first test rarely comes in under half an hour, which is 6.00 €.
Are customer revisions charged separately?
From the third one on, yes. Every half hour of tweaking is 6.00 €, and three revisions take the cost of a custom commission from 41.11 € to 59.11 €.
The practical move is to state the limit before starting: two revisions included, the third is charged. That way the customer sends all the changes at once.
More tools and guides
What you actually keep when you sell 3D prints on EtsyWhat Etsy really takes from each sale in the eurozone: 12.5% normally, 27.5% with Offsite Ads. With the table of what is left at every price.
VAT on selling 3D printed parts: what you actually take homeOf 20 € listed you keep 8.95 €. How VAT works on printed parts, the 10,000 € threshold and the One Stop Shop if you sell to other EU countries.
Break-even point: how many parts you have to sellAt 2.55 € of contribution per part, 100.00 € of monthly fixed costs is 40 parts. And selling on Etsy doubles that figure. The full sums.
3D printing cost calculatorWork out the real cost and selling price of a 3D printed part: material, power, machine wear, failures and markup. Free, no sign-up, nothing uploaded.
How much to charge for a 3D printed partPrice your prints properly: real cost, your labour and your markup. Generates a quote you can copy and send straight to the customer.
How much electricity does a 3D printer useWork out your 3D printer's power use and what it costs per month on your own tariff. With the average wattage of the most common models.