3D Printing Filament Cost & Time

How 3D Printing Cost Is Calculated

A 3D print’s cost is its filament material cost, plus an optional electricity cost. Enter your filament weight and price per kilogram for material cost; optionally add your printer’s wattage, print time, and electricity rate for an electricity estimate.

This is the number to work out before you commit to printing something, whether you’re budgeting for a personal project, comparing two filament brands before buying a spool, or figuring out what to charge if you print things for other people. Your slicer already estimates the filament weight and print time for any given model — this calculator turns those two numbers into an actual dollar figure.

Key Factors to Consider

• This doesn’t account for failed prints or wasted supports/rafts. A slicer’s filament estimate covers the model plus any supports and raft/skirt it generates, but a failed print (adhesion issue, mid-print jam) still consumes filament and electricity with no usable result — budget some margin for failures, especially on longer or more complex prints.
• Filament price varies a lot by material, not just brand. Basic PLA is typically the cheapest filament; PETG, ABS, and specialty filaments (flexible TPU, carbon-fiber-reinforced, dissolvable supports) commonly cost noticeably more per kilogram — use your actual filament’s price, not a generic average, for an accurate estimate.
• This doesn’t include printer wear, maintenance, or your own time. Nozzles wear out, belts need occasional tensioning, and build plates need replacing eventually — none of that is captured in a per-print material-and-electricity estimate. If you’re pricing prints for resale, factor in these longer-run costs and your own labor separately.
• Electricity rates vary by time of day and region. If your utility charges different rates at different times (a common structure for residential electricity), use the rate that applies when you’d actually be printing for the most accurate electricity estimate.

Interpreting Your Results

The total this calculator returns is a material-and-electricity cost floor, not necessarily the price a print is actually worth — a few things are worth knowing about how it relates to a real print job:

• Your slicer’s filament estimate is close, but not exact. It’s based on the model’s sliced geometry, but real-world factors like a filament’s actual density (which can vary slightly by color and manufacturer, even for the “same” material), nozzle purge/prime lines, and a partially clogged nozzle needing a restart can all shift actual usage a little from the estimate. If you want a genuinely precise figure for a specific print, weigh the spool before and after printing on a kitchen scale and use that difference instead of the slicer’s number.
• A full spool is rarely used down to zero. Filament is commonly sold in whole-kilogram (or whole-pound) spools, and most people don’t track cost per remaining gram as a spool empties out — this calculator’s price-per-kilogram field assumes you know (or are estimating) that rate, not that you’ll use an entire spool on one print.
• If you’re pricing prints to sell, this number is a starting floor, not your price. Material and electricity are real, direct costs, but they’re usually the smallest part of what a print is actually worth once you account for your design/setup time, printer depreciation, failed-print risk, and any post-processing (support removal, sanding, painting) — see the FAQ below for more on pricing prints for resale.

The Formula

$$\vD{\text{Material Cost}} = \frac{\vA{\text{Filament Weight (g)}}}{1000} \times \vB{\text{Price per Kg}}$$ $$\vE{\text{Electricity Cost}} = \frac{\vF{\text{Printer Watts}}}{1000} \times \vC{\text{Print Time}} \times \vG{\text{Electricity Rate}}$$

Worked Example

250 g of filament at $20/kg, printed over 4 hours on a 120W printer at $0.15/kWh:

1. Material: $\vD{\text{Material Cost}} = \frac{\vA{250}}{1000} \times \vB{20} = \vD{\$5.00}$.
2. Electricity: $\vE{\text{Electricity Cost}} = \frac{\vF{120}}{1000} \times \vC{4} \times \vG{0.15} \approx \vE{\$0.07}$.
3. Total: $\$5.00 + \$0.07 = \$5.07$.

Useful to Know

Don’t leave a 3D printer running unattended for long, unmonitored stretches — especially overnight or while you’re away from home. A print can run for many hours with a heated nozzle and heated bed the entire time, and safe-use guidance (like UL’s own institutional 3D-printing guidelines, cited below) consistently identifies unattended operation — nobody nearby to notice or respond to a fault — as one of the biggest fire-risk factors. If you regularly run long prints, consider a printer with thermal-runaway protection (a feature that shuts the printer down if a heater’s temperature sensor reports an abnormal reading), a nearby smoke detector, and — if your printer supports it — a camera or smart plug you can check or remotely cut power with. None of this changes the cost math above, but it’s worth knowing before you queue up an overnight print.