Hong Life CalculatorsUnderstanding the 3D printer buy vs outsource calculator — concept and principle
This calculator compares buying your own 3D printer with paying a print service for every part. It totals both options over the years you will use the printer, finds the break-even number of parts and estimates the payback time. Workshops, schools, designers and hobbyists use it before buying a machine.
How it is calculated
- Variable cost per part VC = material + other running cost + your labour per part
- Parts over the period N = parts per year × years
- In-house cost = printer price + maintenance per year × years + VC × N
- Outsourcing cost = outsourcing price per part × N
- Break-even parts = (printer price + maintenance × years) ÷ (outsourcing price − VC), rounded up
- Months to pay back = printer price ÷ ((outsourcing price − VC) × parts per year ÷ 12 − maintenance ÷ 12)
If the service price is not above your variable cost, buying never breaks even and that figure stays blank.
The principle
This is a make-or-buy decision, so only costs that differ between the choices count. The printer and its maintenance are fixed costs you take on only if you buy; each part printed yourself then saves the service price minus your variable cost. Break-even is where those savings cover the fixed costs. Costs paid either way, such as rent, are left out, and the printer is assumed to have no resale value.
Worked example
Defaults: printer 1,500, material 3.50, other running cost 0.80, labour 4.00 per part, maintenance 150 per year, outsourcing 18 per part, 200 parts per year for 3 years.
- VC = 3.50 + 0.80 + 4.00 = 8.30 per part; N = 200 × 3 = 600 parts.
- In-house cost = 1,500 + 150 × 3 + 8.30 × 600 = 1,500 + 450 + 4,980 = $6,930, or 6,930 ÷ 600 = $11.55 per part.
- Outsourcing cost = 18 × 600 = $10,800.
- Saving with the cheaper option = 10,800 − 6,930 = $3,870, so printing in-house is cheaper.
- Break-even = (1,500 + 450) ÷ (18 − 8.30) = 1,950 ÷ 9.70 = 201.03, rounded up to 202 parts.
- Monthly saving after maintenance = (9.70 × 200 − 150) ÷ 12 = 149.17; payback = 1,500 ÷ 149.17 = 10.1 months.
| Outsourcing price per part (incl. shipping) | Saving with the cheaper option |
|---|---|
| 4.5 | $4,230 |
| 9 | $1,530 |
| 13.5 | $1,170 |
| 18 | $3,870 |
| 22.5 | $6,570 |
| 27 | $9,270 |
| 36 | $14,670 |
How to read the result
Planned volume well above break-even favours buying. Near break-even, small changes in volume, failure rate or the value of your time can flip the answer, so test scenarios. A payback well inside the printer's useful life is a good sign.
Common mistakes
- Setting labour to zero for a business.
- Forgetting failed prints and supports in material per part.
- Comparing against a service price without shipping.
Frequently asked questions
How many parts do I need to print for a 3D printer to pay off?
Divide the printer price plus maintenance over the period by the saving per part (service price minus your own variable cost). The calculator rounds this up to whole parts.
Should I include electricity?
Yes. Put power, nozzles, resin tanks and the share of failed prints into the other running cost per part.
Is outsourcing better for low volumes?
Usually, because the printer's fixed cost is spread over too few parts.
Sources: OpenStax, Principles of Accounting, Volume 2: Managerial Accounting, section 10.3 "Evaluate and Determine Whether to Make or Buy a Component"