3D Printing Cost, Pricing, and ROI: How to Know What a Print Really Costs

Filament grams × spool price is a cost fragment, not a quote. A $0.80 part that ate two hours of babysitting and a failed first attempt is how side hustles lose money.

This page is a worksheet. Fill the blanks with your spool invoice, your utility bill, and your clock. Do not copy someone else’s “$X per hour” from a forum. This is not tax, legal, or accounting advice.

If you are still deciding whether to buy a machine at all, start with buy vs outsource.

Why filament cost alone is a bad price

The slicer reports grams and hours. It does not report:

• The time you spent repairing the mesh and answering “can you make it red?”
• The raft you threw away
• The nozzle you will replace after abrasive filament
• The marketplace fee that comes out after you already shipped

Price from fully loaded cost, then add margin.

Material cost

Material $ = (grams used including purge/supports / 1000) × ($ per kg on the invoice)
            + waste grams you already know you will toss

Use the paid kilogram price (shipping included if you want honesty). Do not use a “street average.” Hygroscopic filament that you reprint after a wet week is a material cost, not bad luck.

Machine time and depreciation

Pick a useful life you believe (hours or years) and a purchase price you actually paid (printer + essential enclosure/dryer if you needed them to take the job).

Machine $/hour = purchase $ / expected productive hours
Machine $      = Machine $/hour × slicer hours (or measured hours)

If you do not know productive hours, leave this line blank and treat it as a risk, not as $0. A machine sitting idle still ages; a machine running 24/7 needs maintenance in the next line.

Electricity

Do not invent a wattage. Read the PSU label as a ceiling, then measure if you can (kill-a-watt / smart plug) for a representative job. Your utility’s kWh rate is on the bill — it varies by region and season.

Electricity $ = (average kW while printing × hours) × $ / kWh from your bill

Heated beds and enclosures move this number. PLA on an unheated-ish job is not ABS overnight.

Labor: prep, monitoring, post-processing

Clock four buckets once on a typical job, then reuse the template:

Labor $ = (total hours) × the wage you would pay someone else to do it

If you pay yourself $0, you are volunteering. That is a hobby, not a quote.

Failure/reprint allowance

Use your last 20 jobs, not a blog’s 5%.

Failure multiplier = 1 / (1 − fail rate)
  example: 1 fail in 10 → 1 / 0.9 ≈ 1.11
Loaded material+machine+power $ = those lines × multiplier

Calibration (tuning guide) is how you shrink this line.

Consumables and maintenance

Nozzles, sheets, PTFE, IPA, gloves, FEP (resin), filters, belts. Either:

• Keep a monthly receipt pile and divide by hours printed that month, or
• Add a percent of material you will revise after a quarter of real data.

Do not invent a universal “$2 per print.”

Fees, packaging, shipping and overhead

Add what the channel actually charges this month (Etsy, Shopify, PayPal, Stripe — read the current fee page). Add boxes, labels, tape. Add rent/insurance only if you already allocate them to this activity.

Excluded here: sales tax collection, income tax, entity choice, insurance legalities. Ask a professional in your jurisdiction.

Margin vs markup

Price = fully loaded cost / (1 − target margin)

If cost is $10 and you want 40% margin, price is $10 / 0.60 ≈ $16.67, not $14.

Break-even and ROI

Jobs to break even on a new printer =
  (cash you still owe on the machine) /
  (average profit per job after the costs above)

If you cannot estimate average profit because you have no jobs, you do not have an ROI — you have a purchase decision.

Worked examples

The numbers below are labels, not recommended rates. Replace every ___.

Example A — one-off PLA gadget (hobbyist quoting a neighbor)

Example B — small batch of identical PETG clips

Amortize slice time across the batch. Material and machine time scale; messaging does not. If batch-two is cheaper, say so in the quote so the customer does not expect one-off pricing forever.

When a job is not worth taking

Walk away when:

• The file is a mess and the customer will not pay repair time
• The material needs an enclosure/dryer you do not have
• The deadline assumes a first-try miracle
• The “simple” multi-color purge will cost more plastic than the part
• You would have to invent a number to make the quote look cheap

Cost worksheet (copy into a spreadsheet)

Sources

• U.S. EIA electricity data — regional rates vary; use your bill
• Your filament invoice and TDS (density if you convert volume → mass)
• Current fee pages for the marketplace/processor you actually use
• Slicer mass/time estimates — verify on a scale once