Filament Cost Calculator
A 20% failure rate costs 25%, not 20%.
A 20% failure rate costs 25%, not 20%. Length, volume, mass and full cost of a print, including electricity, printer wear and a failure allowance.
Cost per finished part
2.42
100 g · 33.5 m of PLA · 80.6 cm³
Length, volume and mass convert exactly. A 1.75 mm filament has a cross section of 2.405 mm², so a metre is 2.405 cm³ and, in PLA, 2.98 g — which is the part people get wrong estimating a spool by eye. A failure rate costs more than it looks. At 20% you need 1.25 attempts per finished part on average, so the allowance is 25% of the cost, not 20%. At 50% it is a full 100%. Filament is usually the smallest line on this list for a long print. Six hours of a 100 W printer at ordinary rates costs pennies, but printer amortisation over a realistic lifetime often exceeds the plastic.
How the Filament Cost Calculator works
Length, volume, mass and full cost of a print, including electricity, printer wear and a failure allowance. Length and mass convert exactly; everything else is your own numbers.
Also known as: how much does a 3d print cost · filament grams to metres · how much filament on a 1kg spool · 3d printing cost per part
Where to go next
The Filament Cost question rarely arrives on its own. These are the ones that usually come with it:
- Loan & EMI Calculator — Monthly payment, total interest, and a full amortization schedule.
- Mortgage Calculator — Full monthly cost including tax, insurance, and PMI.
- Car Affordability Calculator — Worked back from income, with running costs taken out first.
- Auto Refinance Calculator — The monthly saving, against what it costs over the life.
Not financial advice. This calculator is for planning and illustration, not financial advice. Real products carry fees, taxes, and terms it does not model. Confirm figures with your lender or a qualified adviser before committing.
Frequently asked questions
How much filament is on a 1 kg spool?
About 335 metres of 1.75 mm PLA, or 125 metres of 2.85 mm. Length goes with the inverse square of diameter, so the thicker filament is far shorter for the same mass.
How do I convert filament length to weight?
A 1.75 mm filament has a cross section of 2.405 mm², so a metre is 2.405 cm³. Multiply by density, 1.24 for PLA, to get about 2.98 g a metre.
Why is a 20% failure rate a 25% cost increase?
Because you need 1/(1−0.2) = 1.25 attempts per finished part. The allowance is a share of successes, not of attempts, which is why it always exceeds the raw rate.
What does it cost to run a 3D printer?
Very little in electricity — six hours at 100 W is under a unit. Printer amortisation over a realistic lifetime usually exceeds both the electricity and, on short prints, the plastic.
Does material choice change the cost much?
Through density as well as price. ABS is less dense than PLA, so the same volume of part weighs less and a spool goes further, partly offsetting the higher price per kilo.
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