MakerKiln

Filament Calculator

Length ↔ weight by real material density, plus a spool-left mode: weigh the spool, get the meters remaining.

Filament

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Local onlyThe conversion math runs in this tab, your entries stay in this browser's local storage, and the page works offline once loaded. Nothing is uploaded.

Slicers report filament use in grams, spools are sold by the kilogram, and half the questions in between — will this print fit on what's left? — are really length questions. The conversion runs through two numbers: the material's density and the filament's cross-section. A kilogram of 1.75 mm PLA is about 335 meters; the same kilogram in dense polycarbonate is meaningfully shorter, and in 2.85 mm anything it's roughly a third of the length.

The spool-left mode is the practical one: put the whole spool on a kitchen scale, enter the empty spool's weight (most brands print this tare weight on the side, or use 200 g as a fair guess), and read off the grams, meters, and percentage remaining — enough to know whether tonight's print makes it.

Questions this tool gets asked

How many meters of filament are on a 1 kg spool?

It depends on the material's density and the filament diameter. For 1.75 mm filament: PLA is about 335 m per kg, PETG about 327 m, ABS about 400 m, and TPU about 344 m. Denser materials pack fewer meters into the same kilogram. This calculator does the exact conversion for any weight, material, and diameter.

How do I know how much filament is left on a spool?

Weigh the whole spool on a kitchen scale, then subtract the empty spool's weight — the difference is the filament left. Empty spools typically weigh 130–250 g depending on brand (many print the tare weight on the spool side). The Spool-left mode here does the subtraction and converts the remainder to meters and a percentage.

Why does filament diameter matter for the conversion?

Weight converts to length through the filament's cross-section area. 2.85 mm filament has about 2.65× the cross-section of 1.75 mm, so a kilogram of it is proportionally shorter. Pick the diameter your printer uses — 1.75 mm is the overwhelming standard on modern machines.

Are the density presets exact?

They are typical published densities — PLA 1.24, PETG 1.27, ABS 1.04, TPU 1.21 g/cm³ — and real filaments vary a few percent by brand, pigment, and additives like carbon fiber. If your spool's datasheet lists a density, type it in over the preset for an exact answer.

Does anything I enter leave my browser?

No. The conversion runs in this tab, your entries are remembered in this browser's local storage only, and the page works offline once loaded. Nothing is uploaded.

How much does 1 meter of 1.75 mm filament weigh?

Roughly 3 grams for PLA (1.24 g/cm³), 3.05 g for PETG, and about 2.5 g for ABS — one meter of 1.75 mm filament is 2.405 cm³ of plastic, so weight is density × 2.405. Flip the calculator above to length → weight, enter 1 m, and it computes the exact figure for any material or diameter.

How long does a 1 kg spool of filament last?

In distance, about 335 meters of 1.75 mm PLA. In practice: at a typical 10 g/hour average print rate, a spool is roughly 100 print-hours — a month of evening printing, or one large helmet. Trinkets of 10–30 g yield 30–100 prints per spool. Use weight → length above to see the meters, and your slicer's per-print grams to divide the spool.

How can I tell how much filament is left without a scale?

A kitchen scale is by far the most accurate route (weigh, subtract the empty-spool tare — that is the Spool-left mode above). Without one, you can only estimate: measure the wound diameter; when the remaining wind is down to a couple of centimeters over the hub on a standard 1 kg spool, you have very roughly 100–150 g left. For any print that matters, weigh it — a $10 scale beats every eyeball method.

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