Filament & model calculators

Every filament calculator

Filament Remaining Calculator

Put the spool on a kitchen scale, pick the brand (or enter the empty spool's weight), and see exactly how many grams and meters of filament are left — and whether it's enough for the print you're about to start.

Filament Length to Weight Calculator

Enter a length, a weight or a volume and get the other two for any material and diameter. The table below the calculator lists grams per meter and meters per kilogram for every common filament.

3D Model Scale & Bed Fit Calculator

Enter the model's size and either a scale, a target dimension or the printer you want it to fit. Get the new dimensions, whether it fits (including rotated), and how the volume — and therefore print time and filament — changes.

3D Print Time Estimator

For quoting a job or deciding whether a print fits in an evening, before you've sliced it: enter the model's volume and your usual settings and get a ballpark print time and filament weight, with an honest range.

The everyday filament questions

These are the ones that come up mid-project, usually when you are about to start a print and want to know whether it will finish. None of them are difficult; they are just tedious enough that people guess instead, and guessing about whether 400 g remains is how a twelve-hour print fails at hour eleven.

How much is left

Weight is the only reliable answer, because you cannot see how many winds are underneath the top layer. Weigh the spool, subtract what the empty spool weighs, and the remainder is filament. The awkward part is the empty weight: a "1 kg" spool sits on a reel weighing anywhere from 12 g for a cardboard refill core to 250 g for a Bambu reusable spool, and that difference is worth a quarter of the print. When a spool does run out, weigh it and write the number down — after a few months you will have exact tares for every brand you buy.

Length, weight and volume

Slicers report all three and they are not interchangeable between materials. A metre of 1.75 mm PLA weighs about 2.98 g; the same metre of ABS weighs 2.50 g, so a kilogram of ABS runs roughly 65 m further. Filled filaments break the pattern harder: metal-filled PLA can be three times the density of plain PLA, so a "1 kg" spool holds a fraction of the length you would expect.

Scaling and fitting the bed

The trap here is that volume scales with the cube of the linear scale. Doubling a model uses eight times the filament and roughly eight times the time; halving it uses an eighth. That is also why scaled parts stop fitting hardware — walls, holes and clearances shrink with everything else, and a 2 mm wall at 50% is thinner than two extrusion lines.

Estimating before you slice

Useful mainly for quoting, when someone asks roughly what something will cost before they send you a file. Expect a pre-slice estimate to land within about 30% for ordinary parts, and further out for anything with many small islands, thin towers or heavy supports. Let the slicer give the final number.