How to use the 3D print cost calculator
- Slice your model and copy the filament weight (grams) — or the length in metres — from the slicer.
- Enter your spool price and spool weight (usually 1 kg).
- Enter the print time, your printer’s average power and your electricity price.
- Optional: add a failed-print allowance, other costs and a markup if you sell prints.
3D printing cost formulas
Filament weight (g) = π × (d ÷ 2)² × length (mm) × density (g/cm³) ÷ 1,000 Filament cost = grams ÷ spool grams × spool price Electricity = watts × hours ÷ 1,000 × price per kWh Print cost = (filament + electricity) × (1 + failure %) + other costs Selling price = print cost × (1 + markup %)
Worked example
A 50 g PLA print taking 3 hours on a 120 W printer, with a $20 1 kg spool and electricity at $0.15/kWh:
- Filament = 50 ÷ 1,000 × $20 = $1.00
- Electricity = 120 × 3 ÷ 1,000 = 0.36 kWh × $0.15 = $0.054
- Total = $1.05; with 10% failures $1.16; at 100% markup $2.32
Filament weight per metre
| Material | Density | 1.75 mm (g/m) | 2.85 mm (g/m) | Metres per 1 kg (1.75 mm) |
|---|---|---|---|---|
| PLA | 1.24 | 2.98 | 7.91 | 335 |
| PETG | 1.27 | 3.05 | 8.10 | 327 |
| ABS | 1.04 | 2.50 | 6.63 | 400 |
| ASA | 1.07 | 2.57 | 6.83 | 389 |
| TPU | 1.21 | 2.91 | 7.72 | 344 |
| Nylon | 1.14 | 2.74 | 7.27 | 365 |
Hidden costs to include when selling
- Machine wear: nozzles, belts, build plates and eventually the printer itself. Many sellers add $0.10–0.50 per print hour.
- Your time: modelling, slicing, removing supports, sanding and painting often cost more than the filament.
- Packaging, fees and shipping for online orders.
- Supports and purge waste: multi-colour printers can waste a lot of filament on purging — check the slicer’s total, not just the model weight.
- Drying and storage: damp filament causes failures; dryer electricity is a small but real cost.
- Test prints and calibration: first-layer tests and tuning prints use filament that never becomes a product, so spread that cost across your sales.
What about resin (SLA/MSLA) printing?
Resin printers use liquid photopolymer sold by the litre or kilogram instead of filament. To cost a resin print, take the model volume in millilitres from your slicer (Chitubox, Lychee), add supports and roughly 10% for resin left on the build plate and in the vat, and multiply by your price per millilitre. Most standard resins weigh about 1.1 g per mL, so a 1 kg bottle holds roughly 900 mL. Resin printers draw less power than FDM machines, but remember the isopropyl alcohol for washing, gloves, FEP film and curing time — they often add more cost than the electricity.