Filament cost calculator
Work out the cost of filament per gram, and the cost of the material in one print. Type in what the spool cost and what it weighs, then the weight of the part from your slicer: the calculator adds purge and failed prints, and works for PLA, PETG, ABS or anything else sold on a spool.
The plastic, not the plastic plus the reel.
What the slicer says the part weighs.
Purge towers, brims, and the odd failed print.
A worked example
The figures the calculator opens on, worked by hand: a $25 spool holding 1000 g of filament, and a part your slicer weighs at 120 g.
- Price per gram: $25 ÷ 1000 g = $0.025 a gram.
- The material in the part: 120 g × $0.025 = $3.00.
- Purge and failures: $3.00 plus 5% = $3.15. That is the figure in the calculator, and $0.0263 a gram once the waste is counted.
Filament is one line of what a print costs. The 3D print cost calculator adds print time, your own hours, the printer’s wear and your margin, and LayerFlow3D works all of it out on every order from your own spools and printers.
What each number means
Spool price
What you paid, including delivery if you paid it. A spool that cost $25 and $6 to ship costs $31.
Spool weight
The plastic, not the plastic plus the reel. A "1 kg spool" is a kilo of filament on a reel that weighs a couple of hundred grams more.
Filament in the part
What the slicer says the part weighs. Supports and rafts count - they came off the same spool.
Purge and waste allowance
Purge towers, brims, skirts and the odd failed print. Five per cent is a careful shop with a single-material printer; a multi-colour machine purging between every layer change is far higher.
Questions people ask
How do I work out filament cost per gram?
Divide the spool price by the grams of plastic on it, then add your waste allowance. A $25 spool holding 1000 g is 2.5 cents a gram before waste, and about 2.6 cents after a 5% allowance.
Does a 1 kg spool really hold 1 kg?
The filament does. The reel it is wound on does not count, so weigh an empty reel of the same brand once and subtract it if you are working backwards from a kitchen scale.
Why add a waste allowance at all?
Because a spool does not all become parts. Purge towers, brims, skirts and failed prints come off the same spool, and a shop that prices at the bare part weight is quietly paying for all of it.
Is cheap filament worth it?
Sometimes. Work out the cost per gram including the failures it causes: a spool that is 20% cheaper and fails one print in ten is not cheaper.
Can I track this per spool rather than per brand?
That is what LayerFlow3D does. Each spool is tracked by weight as it is used, so an order shows what that particular spool cost you.
Know what every spool on the shelf is worth
LayerFlow3D tracks each spool by weight as it is used, so material cost on an order is what that spool actually cost you - not an average, and not a guess.