Guide

The 3D Printing Cost Formula

By the Tools Kit team at QANEN · updated 1 October 2026 · figures verified against published sources on that date

The formula that holds a print's real cost in one line: Cost per good print = [(material + electricity + depreciation + consumables) ÷ (1 − failure rate)] + your labour. Four inputs and one adjustment — and in 2026 the numbers are easier to get right than most makers think: PLA averages about €0.02 per gram (Spoolhound index, €19.81/kg on 1 October 2026), a desktop printer burns 1–3 cents of electricity an hour, and a full hands-on hour of your time usually costs more than everything else combined. This guide builds each term, works one example end to end, and links the free calculators that do the math for you.

Term 1 — Material: weight, not time, sets your floor

Material cost = grams printed × your spool price per gram. Convert any spool price by dividing by its weight: a €19.81/kg PLA spool is €0.0198/g, a $22/1 kg spool is $0.022/g. Count every gram the printer lays down, not just the part: supports, brims, rafts, purge towers and the failed last layer of the previous attempt all come out of the spool. Most slicers report filament used per print; when one doesn't, the material calculator estimates grams from model volume and fill, and the filament cost calculator turns your real spool price into cost per gram and per print.

Term 2 — Electricity: real, tiny, and wildly overestimated

Electricity = (average watts ÷ 1,000) × hours × your €/kWh rate. A desktop FDM machine averages roughly 50–150 W while printing (hotend and bed pulses; an enclosure spikes higher), so at a typical $0.15–0.20/kWh an eight-hour print costs something like $0.06–0.12. It is the smallest term in the formula — if you have ever killed a sale by padding "power costs", this is the evidence to stop. Resin printers draw less (often under 60 W) but add wash-and-cure time and chemistry below.

Term 3 — Depreciation and maintenance: the machine is spending itself

Depreciation per hour = machine price ÷ realistic service hours. Entry machines are commonly planned around 2,000–4,000 printing hours before major wear, which puts a $250 printer at roughly $0.06–0.13 an hour and a $1,000 machine at $0.25–0.50. Add a small maintenance allowance on top (nozzles, belts, PTFE tubing; FEP films and vat liners for resin). It looks trivial per hour and stops looking trivial in print-farm math — which is why the 3D printing cost calculator carries depreciation as a first-class line instead of hiding it in "power".

Term 4 — Failure rate: the only term that multiplies everything else

Prints fail: layers shift, first attempts curl, the 9th hour dies at the 9th layer. Community experience puts a healthy machine near 10% failure as normal. Because a failed print consumes material, power and machine-hours while producing nothing, the adjustment divides rather than adds: material + machine costs ÷ (1 − 0.10) = an 11% surcharge. Your own rate is measurable — tally successes per file for a month; new files and long prints deserve a higher personal number than the average.

Term 5 — Labour: the line that decides whether you're a business

Slicing, file repair, support removal, sanding, priming, packing, and for resin the wash-and-cure cycle — all of it is hours, and the norm worth paying yourself is ≥ $20/hour (design and custom modelling work prices far higher; see the modeling hourly-rate calculator). This term is why two identical prints can legitimately cost very different amounts: one drops off a calibrated machine unassisted, the other needs forty minutes of finishing.

One worked example, end to end

A 25 g PLA desk accessory: 2-hour print on a $250 machine, 100 W average draw at $0.17/kWh, 10% failure history, 15 minutes of hands-on prep and packing at $20/hour:

Term	Math	Cost
Material	25 g × $0.02/g	$0.50
Electricity	0.1 kW × 2 h × $0.17	$0.03
Depreciation	$250 ÷ 3,000 h × 2 h	$0.17
Failure adjustment	$0.70 ÷ (1 − 0.10)	+$0.08
Labour	0.25 h × $20	$5.00
True cost per good print	sum	≈ $5.78

Look at the shape of that number: 87% of the cost is labour — everything the machine consumed, filament, electricity, wear and the failed print allowance included, is the other $0.78. Pricing, markups and marketplace fees are the next step — the 3D print pricing guide turns this cost figure into a selling price, and the print time calculator keeps hours honest when slicer estimates are optimistic. For resin's different shape (chemistry, consumables, whole-batch failures), the resin cost calculator runs the same formula with resin inputs.

Frequently asked questions

What is the 3D printing cost formula?

Cost per good print = [(material + electricity + printer depreciation + consumables) ÷ (1 − failure rate)] + your labour. Material is print weight × your spool price per gram; electricity is average watts ÷ 1,000 × hours × your kWh rate; depreciation is printer price ÷ realistic service hours × print time.

How much does it cost to run a 3D printer per hour?

Machine-run cost alone is small: a typical desktop FDM printer draws roughly 50–150 W while printing, so at ~$0.15–0.20/kWh electricity is 1–3 cents per hour. Add about 8 cents/hour depreciation for a $250 printer rated to ~3,000 hours. The hour itself is cheap — the filament you melt and the failures you eat are what actually cost.

How much does a spool of filament cost in 2026?

Spoolhound's live price index averaged €19.81 per kg for PLA on 1 October 2026 (PETG €18.75, ABS €21.86) across tracked stores, with the market roughly spanning €15–30/kg depending on brand and finish. That works out to about €0.02/g — so a 25-gram part uses ~€0.50 of material before anything else counts.

Should I include failed prints in my cost?

Yes — it is the most-skipped term. Around 10% failure is normal in the community's experience, even on tuned machines. Divide your material + machine subtotal by (1 − failure rate): at 10% that is an 11% surcharge on those lines, and more on new files, exotic materials or long prints that fail late.

Does printer depreciation really matter?

A little: a $250 printer with a ~3,000-hour service life "spends" about $0.08 per printing hour, which is real but rarely the deciding number. It matters more on $1,000+ machines ($0.33+/hour), in print-farm math, and when pricing long prints — add maintenance (nozzles, belts, PTFE, resin FEPs) as a small percentage on top.

Why is my time the biggest line in the formula?

Because it dwarfs the rest: an hour of slicing, support removal, sanding or wash-and-cure at even $20/hour outweighs the material and electricity of almost any single small print combined. The community norm is to pay yourself at least $20/hour for hands-on work — if a price cannot absorb that, it is a hobby rate, not a selling rate.

Is resin cheaper to print than filament?

Per printed gram they can land in a similar band, but resin adds consumables (IPA or water-wash chemistry, gloves, FEP films, filters) and post-processing time (wash, cure), while filament failures are usually visible early and resin failures are often total-batch losses. The honest answer is model both — the resin and filament cost calculators use the same formula as this guide.

Sources & verification. Filament price benchmarks: the Spoolhound price index, read 1 October 2026 (PLA €19.81/kg average across 40 tracked stores; PETG €18.75; ABS €21.86). Power draw, service-life hours and the 10% failure norm are community consensus ranges as cited in our pricing guide — your electricity tariff, spool prices and measured failure rate replace them in the calculators. Worked example uses round illustrative figures ($0.02/g, $0.17/kWh, 3,000 h service life). Not legal or tax advice.

Live