What Does a 3D Print Really Cost? I Built a Calculator to Find Out

Filament is the smallest problem

Ask anyone with a 3D printer what a print costs and you'll usually get one number: grams of filament times price per kilo. It's the easiest cost to see — it sits on the spool label — and for most small jobs it's not even close to the biggest one.

I have a printer at home, and every time someone asked me to print something for them I ended up doing the same back-of-the-envelope maths and getting it wrong in the same direction: too cheap. So I built a small tool to do it properly and put it on the site: 3D Print Calculator.

It's free, runs in the browser, and works in any currency — the currency field is just a label, the maths is the same.

What goes into the price of one plate

The calculator splits the cost of a single build plate into five parts:

1. Filament — grams per plate (including supports and brim, which people forget) times price per kilo.
2. Electricity — printer wattage × print hours × your price per kWh.
3. Printer wear — the printer's price divided by how many hours of printing you expect from it before it's worn out, times the print time. The machine is a consumable; it just wears out slowly.
4. Labour — your hands-on minutes per plate (slicing, setup, removal, cleanup) at your hourly rate. Not the print time — the time you spend.
5. Failed prints — the plates you have to run again.

Then it adds packaging per piece, divides by the number of pieces on the plate, and applies your markup to get a suggested price.

A worked example

Take a modest job: one piece per plate, 100 g of filament at 20 USD/kg, a 5-hour print on a 120 W machine at 0.20 USD/kWh, a 500 USD printer expected to last 5,000 hours, 15 minutes of hands-on time at 20 USD/h, a 10% failure rate, 1 USD of packaging and a 2× markup.

• Filament: 2.00 USD (24%)
• Electricity: 0.12 USD (1%)
• Printer wear: 0.50 USD (6%)
• Labour: 5.00 USD (59%)
• Failed prints: 0.85 USD (10%)

Total per plate: 8.47 USD

With packaging, one piece costs 9.47 USD. At 2× the suggested price is 18.93 USD, leaving 9.47 USD profit — a 50% margin.

Look at the shares. Filament is a quarter of the cost. Electricity barely registers. Labour is almost 60%. Fifteen minutes of your time is worth more than the plastic. If you price by grams, you're giving away your time for free.

Failed prints: divide, don't add

This is the one detail I care most about getting right.

The intuitive way to account for failures is to add the failure rate on top: 10% failures, so add 10%. That undercounts. A failed plate isn't a 10% surcharge — it has to be printed again, and the reprint can fail too.

If 90% of plates succeed, then to get one good plate you need, on average, 1 / 0.9 ≈ 1.11 plates. So the calculator divides the base cost by the success rate instead of marking it up by the failure rate:

• Markup approach: 7.62 × 1.10 = 8.38 USD
• Division approach: 7.62 / 0.90 = 8.47 USD

At 10% the gap is small. At a 30% failure rate — a new material, a tricky geometry, a printer that needs tuning — it's 1.30× versus 1.43×. That difference is your margin quietly leaking out.

Profit per printer hour

Margin is the number people quote. With one printer, it's the wrong number to choose jobs by.

Your printer is the bottleneck: it can run one plate at a time, and every hour it spends on one job is an hour it can't spend on another. Margin ignores time completely. A 30-hour plate and a 5-hour plate can both show a healthy 50% margin and still be very different businesses.

So the calculator also shows profit per printer hour. In the example above it's 9.47 USD over 5 hours — about 1.89 USD per hour. If a big 30-hour plate brings in 25 USD profit, it looks better per piece but earns only about 0.83 USD per hour, less than half. When the queue is full, that's the number that tells you what to print first — and what to price higher or turn down.

Same logic as any capacity-constrained system: optimise for throughput of the bottleneck, not for the margin of a single unit.

Try it

The calculator is here: pelikhovskyi.tech/services/3dprintcalc. Plug in your own printer, your filament prices, your local electricity tariff and — honestly — your real hands-on time and failure rate. The result is usually higher than the number you've been charging.

If you run print jobs as a side business, it's worth a few minutes. If you think a part of the model is missing, tell me.