⚙️ Multi-Material Cost Comparison Calculator
Compare cost per gram across different filament spools — different brands, materials, or bulk sizes — to find your best value.
One number per spool, sorted cheapest first
Every row is reduced to the same unit price and the list is re-sorted on each keystroke, so the cheapest spool always sits at the top with the tick:
cost per gram = spool cost / spool weight (g)The default rows are $20 per 1000 g of PLA at $0.0200/g and $25 per 1000 g of PETG at $0.0250/g. Four decimals are shown because that is where the differences live: half a cent a gram is 31 cents on a 62 g print and $5 across a spool.
| Spool | Cost per gram |
|---|---|
| $18 / 750 g | $0.0240 |
| $20 / 1000 g | $0.0200 |
| $25 / 1000 g | $0.0250 |
| $42 / 2300 g | $0.0183 |
Making the comparison honest
- Enter net filament weight. 750 g and 850 g spools are the trap this tool exists to catch; the empty reel is never part of that figure.
- Add shipping into the cost when one seller charges it and another does not. $6 of postage on a $20 spool is a 30% swing.
- Cost per gram is not cost per print across materials. A fixed volume weighs differently in each plastic: 50 cm³ is 62 g of PLA at $1.24, but 63.5 g of PETG at $1.59.
Frequently asked questions
How do I compare a 750 g spool with a 1 kg spool?
Divide each price by its own weight. $18 for 750 g is $0.0240 a gram, which is worse value than $20 for a full kilo at $0.0200, despite the lower sticker price.
Are bulk filament spools actually cheaper?
Usually yes per gram - a 2.3 kg refill at $42 is $0.0183 against $0.0200 for a 1 kg spool, about 9% less. Whether it helps depends on your printer taking the larger reel and on you using it before it absorbs moisture.
Is PETG worth the extra cost over PLA?
It depends on the part, not the price. PETG survives heat and outdoor UV that softens or embrittles PLA, so it earns its 25% premium on functional and outdoor parts and not on display models.