How to Calculate 3D Printing Cost

A 3D print that uses only a few pounds of filament can still cost more than its material alone. The real cost depends on how much plastic the slicer uses, how long the printer runs, electricity, failed prints and—if you sell parts—the time you spend preparing and finishing them.

The simplest useful calculation is:

total print cost = material + electricity + machine use + labour + extras + failure allowance

For a quick estimate, start with the two values your slicer provides after you prepare the model: filament weight in grams and estimated print time. Those figures are normally more reliable than calculating from an STL alone because the slicer accounts for infill, wall count, supports, layer height and orientation.

Use the 3D Print Cost Calculator to add those values and see the full breakdown.

Calculate filament cost

You need three numbers:

1. Filament used for the print, in grams.
2. The net weight of the spool, usually 1,000 g.
3. The price you paid for that spool.

Use this formula:

material cost = filament used ÷ spool weight × spool price

If a 1 kg spool costs £20 and the slicer says the part uses 80 g:

80 ÷ 1,000 × £20 = £1.60

This is the cost of the plastic used, not the cost of the print as a whole. Include purge material and supports if your slicer includes them. If it does not, add a little contingency rather than pretending the result is exact.

Estimating weight from a model

If you have a model but have not sliced it yet, volume can provide a useful starting point. Material density converts a solid volume into a solid-model-equivalent weight. PLA is commonly around 1.24 g/cm³, while PETG, ABS and TPU differ.

However, a hollow or low-infill print contains much less material than the solid model. Walls and supports work in the other direction. Treat this as a planning estimate only, then replace it with slicer output before quoting a customer.

InspectMesh can calculate model volume for STL files and 3MF files, or use the combined 3D Print Cost Calculator.

Add electricity cost

Electricity is usually a modest cost for a small desktop print, but it should not be ignored on long jobs or when you run several printers.

Use:

electricity cost = printer power in kW × print time in hours × electricity price per kWh

A printer averaging 120 W is 0.12 kW. If it runs for 10 hours and electricity costs £0.30/kWh:

0.12 × 10 × £0.30 = £0.36

Actual power draw changes during heating, movement and idle time. If you want a closer figure, measure your own printer with a plug-in energy meter. Otherwise, use a conservative average and treat it as an estimate.

Include machine use and maintenance

Printers wear: nozzles, beds, belts, bearings, fans and occasional repairs all have a cost. You do not need to predict every replacement part for a hobby print, but an hourly machine-use allowance is sensible when pricing work for customers.

For example, adding £0.25 per print hour to a 10-hour job adds £2.50. The right figure depends on your machine, how heavily you use it and whether you need to recover the printer purchase cost. Keep this separate from electricity so you can adjust it later.

Include your time and extra parts

For personal prints, you may choose to treat your own time as free. For selling prints, do not.

Include time spent on tasks such as:

• repairing or checking the model;
• slicing and preparing the printer;
• removing supports and post-processing;
• quality checking;
• packing and communicating with the customer.

Also add the actual cost of inserts, magnets, screws, paint, packaging and shipping materials. These are easy to forget because they are not part of the slicer estimate.

Allow for failed prints

Failures are part of 3D printing. A small percentage allowance protects you from reprints, supports that fail, material waste and occasional setup errors.

For a reliable, well-tested model, 5% may be enough. For a new design, difficult material or long unattended print, a higher allowance can be more realistic. Apply it to the full pre-failure subtotal, not only filament.

Do not use a failure allowance to hide an uncertain quote. If the model is risky, inspect it first for open edges, non-manifold geometry and other issues with the STL Quality Checker or 3MF Quality Checker.

Add a profit margin only after costs

Your cost tells you what the print consumes. Your selling price also needs to reward your time, skill and risk.

First calculate the total cost. Then choose a margin that makes sense for your market and the value of the finished item. Keep the margin visible rather than mixing it into material or electricity figures; it helps you understand whether a price change comes from higher costs or a deliberate business decision.

A practical workflow

1. Check the model for obvious mesh problems.
2. Slice it using your real printer, material and settings.
3. Copy the slicer’s filament weight and print time.
4. Add electricity, machine use, labour and extras.
5. Add a realistic failure allowance.
6. Add margin only if you are preparing a selling price.

The 3D Print Cost Calculator keeps those inputs in one place and gives you a clear material, energy and total-cost breakdown.