Filament cost calculator

What a spool costs you per gram, and what the plastic in one print is worth once purge and failures are counted. The same material costing LayerFlow3D runs on a real order.

The plastic, not the plastic plus the reel.

What the slicer says the part weighs.

Purge towers, brims, and the odd failed print.

This print costs $3.15 in filament, waste included
Cost per gram $0.0263 what every gram of this spool costs you
Prints per spool 7 before you open the next one

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.

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