Filament calculator: how many meters in 1 kg and what is left on the spool
Enter the length, weight or volume of filament and get the other two, for 1.75 and 2.85 mm and seven materials. Weigh a spool on a kitchen scale to see how much filament is left and whether it will cover the print.
Opens without an account 3 times a day. A free account removes the limit.
- 3 measuresmeters, grams and cm³ both ways
- 7 materialseach with its own density
- Spool leftwithout the empty spool
- Will it be enoughmargin and a 5 % buffer
What a filament length calculator does
The filament length calculator from EduFacturing is a free online tool that converts the length, weight and volume of filament into one another and shows what is left on a spool. It works with 1.75 and 2.85 mm and seven materials.
Three calculations: a two-way conversion, the spool remainder (scale weight minus the empty spool) and a check against the grams the slicer, the program that prepares a print, asks for.
The calculation runs in the browser. For example, 1 meter of 1.75 mm PLA weighs 2.98 g, and 1 kg is about 335 m.
Filament weight to length: meters in 1 kg, grams per meter
Converts meters to grams and back
Enter one of the three fields and the other two are worked out from it. Length shows to 3 decimals, weight and volume to 2.
Uses the density of the chosen material
PLA 1.24, PETG 1.27, ABS 1.04, TPU 1.21, ASA 1.07, Nylon PA12 1.01 and PC 1.20 g/cm³. The first four come from the EDi Brain rules core, the rest from the price calculator.
Works out how much filament is left on the spool
Weigh the whole spool and pick an empty spool: cardboard 130 g, plastic 200 g or your own figure. You get the net weight, the remainder in meters and cm³, and a warning if the spool weighs less than the empty one.
Says whether the filament will be enough
It compares what you have with the slicer grams: Enough with a margin, or Not enough with the missing grams. With a margin under 5 %, it suggests a minimum with a buffer.
How much filament do I need, and what is left
A spool is weighed before the print, not after the printer has run dry.
How much filament is left before a long print
Enter the spool weight from the scale and see the margin against the slicer grams.
How many meters in 1 kg of filament
1 kg of 1.75 mm PLA is about 335 m, and the same weight of ABS is about 400 m.
How many grams of filament for a part
Enter the part volume in cm³ and get grams and meters for the chosen material.
Why 2.85 mm filament is not 63 % heavier
2.85 mm weighs 2.65 times as much as 1.75 mm: area grows with the square of the diameter.
How filament length, weight and volume are worked out
Units are converted in one place: a diameter in mm becomes a cross-section in cm², otherwise the result is off by a factor of 100.
Cross-section
The area of the circle in cm² is worked out from the diameter. For 1.75 mm it is 0.02405 cm².
Remainder
Net weight is the spool weight minus the empty spool, never below zero.
Will it be enough
The margin is available minus needed; the recommended minimum is the needed amount plus 5 %.
| Applies to | Formula | Meaning |
|---|---|---|
| Cross-section | A = π · (d / 2)² | d is the diameter in mm; divide by 100 for cm² |
| Mass from length | m = ρ · L · A | ρ in g/cm³, L in cm, A in cm² |
| Length from mass | L = m / (ρ · A) | the result is in cm; divided by 100 it gives meters |
| Spool remaining | net = gross − spool | a warning shows when gross is below the spool |
| Will it be enough | margin = available − needed; minimum = needed · 1.05 | a 5 % buffer for brim and the purge line |
A filament calculator that subtracts the empty spool
A density for each material
Seven materials, each with its own density, not one figure for all.
The remainder does not count the spool
The empty spool is a separate field with three choices, not zero, so the remainder is not inflated by a hundred grams of plastic.
Nothing is chained
Each value is worked out from your entry, so converting back returns the number to within the rounding of the field.
The weight of an empty spool is typical, not universal: cardboard spools run about 100 to 180 g, plastic ones about 150 to 250 g, and a 100 g difference is over 30 m of filament. For the exact figure, weigh your own empty spool.
The tool does not calculate a part's price, does not track moisture in the filament and does not handle resin. ASA, Nylon PA12 and PC use densities from the price calculator, not from the EDi Brain rules core.
Filament calculator questions
How many meters are in 1 kg of PLA filament?
About 335 m at 1.75 mm (1000 g divided by 2.98 g per meter) and about 126 m at 2.85 mm. For 1.75 mm ABS a kilogram is about 400 m.
How much does 1 meter of filament weigh?
At 1.75 mm: PLA 2.98 g, PETG 3.06 g, ABS 2.50 g. At 2.85 mm one meter of PLA weighs 7.91 g.
How to know how much filament is left on the spool?
Weigh the whole spool on a kitchen scale and subtract the empty spool: cardboard is about 130 g, plastic about 200 g. For example, 1150 g with a cardboard spool is 1020 g of filament, about 342 m.
How do I calculate how much filament I need for a print?
Take the grams from the slicer, or the volume of the part in cm³. The volume gives grams and meters for the chosen material, and the grams show whether the spool is enough.
How much buffer should I leave over the slicer figure?
5 %: brim, the purge line and a failed first layer push real use above the estimate. For prints over 8 to 10 hours the text beside the tool advises a larger margin.
Is the filament length calculator free?
Yes. Without an account it opens 3 times a day. With a free account there is no limit.
The filament calculator is free. Pro opens the rest
Pro costs 15 EUR a month and opens 45 Pro tools.
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Check how much filament you have left
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