How to Calculate 3D Printing Cost: Formula and Example
Quoting a 3D print without knowing the real cost means either losing money or losing the customer. Cost comes from five items: filament, electricity, machine wear, failure risk and labor. In this guide we calculate each one with its formula, using a single example.
The formula in short
Total cost = (filament + electricity + machine wear + labor) × (1 + failure margin)
If you sell your prints, profit, shipping and marketplace fees are added on top; see the pricing guide.
1. Filament cost
For most prints filament is the biggest part of the cost.
Filament cost = grams × (1 + waste) ÷ 1000 × price per kg
Your slicer gives the weight: Bambu Studio, OrcaSlicer, PrusaSlicer and Cura show "filament used" or estimated weight after slicing. Waste is a small margin for supports, purge and first-layer losses, usually 3–10%. For multi-color prints, calculate each filament separately and add them.
Example: 50 g of PLA at $20 per kg with 5% waste → 50 × 1.05 ÷ 1000 × 20 = $1.05.
2. Electricity cost
Electricity = printer power (W) ÷ 1000 × print time (hours) × price per kWh
A printer's draw from the wall is not constant: it is high while heating, then the heaters cycle. That is why an average value is used. A heated bed and an enclosure increase consumption. For typical values by model see the printer power table.
Example: 110 W average for 3.5 hours → 0.385 kWh. At $0.15 per kWh that is $0.058. On small parts electricity is tiny next to filament; on long, large prints it adds up.
3. Machine wear
Nozzles, belts, bearings, bed surfaces and fans wear out, and the printer itself loses value. A simple approach is to divide the printer price by its expected lifetime in hours. For example a $800 printer with a 5,000-hour life comes to $0.16 per hour (an illustration only; set your own figure). Hobbyists often leave this at zero; if you sell prints you should include it.
4. Failure margin
Not every print succeeds; some stop halfway or detach from the bed. The failure margin spreads the cost of failed prints across the successful ones. 3–5% is reasonable with a well-tuned printer, 10–15% when you work with new materials and complex parts.
Failure margin = (filament + electricity + wear + labor) × failure %
5. Labor and packing
Add hands-on work such as support removal, sanding, painting and packing as a fixed amount per piece. If you only print for yourself you can skip this.
Putting it together
| Item | Calculation | Amount |
|---|---|---|
| Filament | 50 g × 1.05 × $20/kg | $1.050 |
| Electricity | 0.385 kWh × $0.15 | $0.058 |
| Subtotal | $1.108 | |
| Failure margin (5%) | 1.108 × 0.05 | $0.055 |
| Total cost | $1.163 |
This part costs about $1.16. You can do the same calculation with your own numbers in Filanomy in seconds, and even upload your file to fill in the weight and time automatically.
When there are several parts on the plate
The slicer gives total weight and time for the whole plate. If the plate holds 4 parts, divide both by 4 to get the cost per part. The "Parts on the plate" field in Filanomy does this for you.
Common mistakes
- Ignoring electricity completely (it matters on long prints and expensive tariffs).
- Forgetting waste: support and purge weight can sit outside the grams the slicer shows.
- Using the label (PSU) wattage as the printer's power. The real average draw is usually much lower.
- Not counting failed prints in the cost.
- Forgetting shipping and marketplace fees when selling.
Frequently asked questions
Does electricity matter in 3D printing cost?
On a single small part it is usually a few cents, small next to the filament. But for a printer running hours every day the monthly bill becomes meaningful: at 110 W average and 8 hours a day you use about 26 kWh a month.
Is the weight from an unsliced STL accurate?
No, it is only an estimate. Weight depends on infill, wall count and supports. Filanomy gives an approximate value for STL and OBJ files (it can be off by ±30%). For exact weight and time, slice the model and upload the .3mf or .gcode.
How much filament waste should I add?
3–5% is enough for simple parts. Prints with lots of supports, several colors or frequent purging may need 8–10%. Start at 5% and adjust to your real usage.
Calculate for your own part: upload your file and weight and time fill in automatically.
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