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FAQ
Quick answer: These guides cover the math behind hobby 3D printing: what a print costs in filament, how long it takes, and how nozzle size, layer height, filament type and enclosures change both. Start with the filament cost calculator, then pick the guide that matches the setting you want to change.
Guides
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Filament cost questions
How do I work out what one print costs in filament?
Take the filament weight your slicer reports for the job, in grams, and multiply it by your spool price per gram. A 1 kg spool that cost $20 works out to $0.02 per gram, so a 50 g print uses about $1 of plastic. Add a small allowance for purge lines, supports and failed starts; many hobbyists add 5 to 10 percent. The filament cost calculator does this math for you, and the cost per print guide walks through it step by step.
Why does my slicer show meters instead of grams?
Some slicers report filament length. To convert, you need the filament diameter and the material density. For 1.75 mm PLA, one meter weighs roughly 3 grams, so 10 m is about 30 g. Different materials have different densities, so check the number on your spool label. Our grams to meters guide shows the formula.
Do layer height and build volume change the cost?
Layer height changes time far more than material, because the same solid volume still has to be filled. Infill percentage, wall count and model size change material the most. A bigger model scales cost with volume, not height, so doubling every dimension can mean roughly eight times the plastic. See cost by layer height and cost by build volume.
Print time questions
Why is my print taking longer than the slicer estimate?
Slicer estimates assume the printer reaches every programmed speed. Real printers slow down for acceleration limits, short moves, cooling minimums on small layers and retractions. Treat the estimate as a starting point and compare it to a few finished prints on your own machine. The print time estimation guide explains the main factors.
How much does a finer layer height add?
Print time grows roughly in proportion to the number of layers. Going from 0.2 mm to 0.12 mm layers means about 1.7 times as many layers, so a four-hour job can approach seven hours. Read print time by layer height and layer height and surface quality to choose the trade-off.
Does filament type change print time?
Yes. Flexible filaments such as TPU usually print slower to avoid jams, and PETG is often run a little slower than PLA for clean layers. Check the speed range your filament maker lists. See print time by filament type.
Nozzle questions
Should I switch to a bigger nozzle?
A 0.6 mm nozzle lays down more plastic per pass than the common 0.4 mm size, which can cut time on large, simple parts. You give up fine detail and small text. Many hobbyists keep a 0.4 mm nozzle for detailed models and swap to a larger one for functional parts. Compare options in nozzle size and print speed, print time by nozzle size and nozzle sizes for different printers.
What layer height works with my nozzle?
A common rule of thumb keeps layer height between about 25 and 75 percent of nozzle diameter. For a 0.4 mm nozzle, that is roughly 0.1 to 0.3 mm. Your printer maker's guidance takes priority. More detail is in nozzle and layer height trade-offs.
Material questions
Which filament should a beginner start with?
PLA is the usual starting point: it prints at lower temperatures, rarely needs a heated chamber and is widely sold. PETG is tougher and handles more heat but can string. TPU is flexible and slower to print. ABS needs higher temperatures and usually an enclosure to avoid warping. Compare them in PLA vs PETG vs TPU and PLA vs ABS vs PETG, and always follow the temperature range on your spool.
Enclosure questions
Do I need an enclosure?
Not for most PLA printing. An enclosure helps keep chamber air steady, which reduces warping and cracking with materials such as ABS, and it cuts drafts in cold or busy rooms. It can also lengthen warm-up time. Read enclosure benefits, enclosure options and enclosure vs open-frame printers.
Can an enclosed printer overheat PLA?
It can. PLA softens at fairly low temperatures, so a fully closed chamber may cause clogs or soft parts. Many owners open a door or lid for PLA. Check your printer maker's advice for your model and see print time with enclosures.
Ventilation questions
How should I ventilate my printing space?
Heated printing releases particles and vapors, and the amount varies by material and temperature. We do not rate any setup as risk-free. Follow the guidance from your printer and filament makers, print in a room with fresh air exchange where you can, and avoid sitting next to the printer for long runs. Our ventilation guidance, ventilation by filament type and ventilation with enclosures pages collect the general points, and they do not replace maker instructions or local safety advice.
About this site
Do you test printers or earn money from links?
The figures here are worked estimates, not lab test results. We do not have affiliate links on these pages today; any future program would be listed on our disclosure page first. Questions or corrections are welcome at hello@charlandandco.com.