Key takeaways
- Material is the easiest part to calculate and usually the smallest part of the cost.
- The failure rate belongs in the formula. A real workshop reprints 5–15 % of jobs.
- Labour for post-processing often matches or exceeds the material cost.
- Print time drops noticeably with a better orientation and a larger nozzle — usually cheaper than changing material.
Most 3D printing quotes are wrong because they count only the two things that are easy to measure: grams of plastic and machine hours. The slicer gives you both, so people add them up, apply a multiplier and call it a price. A few months later the workshop discovers it is working for nothing.
The formula below has five parts. The first three are easy; the last two are where the money leaks.
The formula
Cost of one part = the sum of five items
- 1. Material
- part weight (g) ÷ 1000 × price per kg, plus support and purge
- 2. Machine
- print hours × (depreciation per hour + maintenance per hour)
- 3. Electricity
- print hours × average power (kW) × electricity price
- 4. Failures
- (sum of the three above) × real failure rate
- 5. Labour
- minutes of preparation and post-processing × labour rate per minute
1. Material — don't just read the slicer's number
The slicer reports the part's weight. But your spool is also consumed in places that aren't in the part:
- Support and brim — on a part with many overhangs this can add 15–30 %.
- Purge and priming — a few grams per print; much more on a multi-colour machine.
- The start and end of the spool — a few tens of grams you can't print, spread across parts.
- Calibration prints — temperature towers and flow tests for a new material.
In practice: take the slicer's figure and multiply by 1.15 for simple parts and 1.3 for parts that need a lot of support.
2. Machine — depreciation is a real cost
A printer has a useful life, and every hour it runs uses some of it. Divide the machine price by its expected print hours over its life, then add consumables:
- Nozzles — much faster with fibre-filled materials.
- Build plates and PEI sheets.
- PTFE tubes, belts, fans, sensors.
- For resin machines: the LCD screen, a large item whose life is counted in exposure hours.
3. Electricity — smaller than people think
A desktop FDM printer draws roughly 0.1–0.3 kW on average, depending on bed temperature and whether it is enclosed. Over a ten-hour print that is 1–3 kWh. It is almost always the smallest of the five items, and people tend to worry about it more than it deserves.
4. Failure rate — the most forgotten item
No workshop has a 100 % success rate. Prints lift off the bed, filament runs out mid-job, parts come out of tolerance, customers change their minds after seeing the prototype. If your failure rate is 10 % and you don't count it, one part in every ten is free.
A failure rate isn't the sign of a bad workshop. Leaving it out of the price is.
Record your real rate per material, because it varies a lot: low for PLA, moderate for PETG, noticeably higher for ABS and nylon — especially on large parts. That is also why difficult materials cost far more than the difference in price per kilogram.
5. Labour — the second most forgotten item
Human time is often treated as free because it doesn't appear in the slicer. Count it:
- Preparing the file, fixing orientation, building supports.
- Preparing the machine, changing material, drying filament.
- Removing the part and supports, sanding, re-drilling holes, fitting threaded inserts.
- For resin: washing, curing, removing supports, handling waste.
- Packing and shipping.
For small parts this often matches or exceeds the material cost. For resin parts that need washing and curing, it almost always does.
A full worked example
A PETG bracket, 85 g according to the slicer, printing for 6 hours. The inputs below are Vietnamese market prices observed on 27/08/2026 and the current electricity tariff — sources on the data sources page. Retail prices for filament and machines move constantly, so check against your own workshop's invoices.
| Item | Calculation | Amount |
|---|---|---|
| Material | 85 g × 1.15 = 98 g → 0.098 × 250,000 | 24,500 VND |
| Depreciation | 6 h × (7,500,000 ÷ 4,000) | 11,250 VND |
| Maintenance, consumables | 6 h × 1,000 | 6,000 VND |
| Electricity | 6 h × 0.2 kW × 3,460 | 4,152 VND |
| Sum of the above | 45,902 VND | |
| Failures at 10 % | 45,902 × 0.10 | 4,590 VND |
| Labour | 25 minutes of preparation + post-processing | 41,700 VND |
| Cost | 92,192 VND |
Two things stand out. First, material is only about 27 % of the cost. Second, labour is the largest item — 45 % — even though the part needs only 25 minutes of handling. Quote on grams of plastic alone and you are ignoring nearly three quarters of the cost. With machines and filament as cheap as they are in Vietnam today, the balance tips even further towards labour.
Cutting cost, in order of effectiveness
- Change the orientation. Less support means less plastic, fewer machine hours and less time removing support. It is the cheapest saving because it requires buying nothing.
- Use a larger nozzle. Going from 0.4 to 0.6 mm often cuts print time by 30–40 % on functional parts, and often makes the part stronger too thanks to the wider extrusion.
- Reduce walls and infill where there's no load. Many parts are printed with 4 walls everywhere when only one face needs them.
- Lower the failure rate. Drying filament and standardising the first layer affect the cost of every part, not just one.
- Change material — last. A cheaper material only helps if it's good enough. A PLA part reprinted because it melted in a car costs more than an ASA part printed once.
If you're comparing materials on price per kilogram, compare the failure rate and machine hours that come with them too. The full catalogue with prices and settings is on the materials page, and the print cost calculator does this arithmetic on your own numbers.
Frequently asked
What goes into the cost of a 3D printed part?
Five items: material (weight × price per kg, plus support and purge), machine time (depreciation and consumables per hour), electricity, the failure rate, and labour for preparation and post-processing. The last two are the most often forgotten and are often about a third of the cost.
What share of the cost is material?
At Vietnamese price levels — retail PLA/PETG around 120,000–420,000 VND/kg and mainstream machines under 10 million VND — material is usually only 25–40 % of the cost. The rest is machine time, electricity, failures and labour. That is why a quote based only on grams is almost always below the real cost.
How much electricity does a 3D printer use?
A desktop FDM printer averages about 0.1–0.3 kW depending on bed temperature and enclosure, so about 1–3 kWh for a ten-hour print. At residential tier 6 (3,460 VND/kWh before VAT, Decision 1279/QĐ-BCT), that is about 3,500–10,000 VND for the whole print — the smallest item in the cost.
What failure rate should I use?
Record your workshop's real rate per material rather than using one general figure. PLA fails less than PETG, and ABS and nylon fail noticeably more, especially on large parts — part of why difficult materials cost far more than the per-kilogram price difference.
What's the fastest way to cut 3D printing cost?
Reorient the part to need less support — it saves plastic, machine hours and support-removal time at once, without buying anything. Then use a 0.6 mm nozzle, reduce walls where there's no load, and lower the failure rate by drying filament.