Remaining Filament Calculator
Weigh your spool and instantly see how much filament is left and whether it is enough for your print.
The empty spool weight is often printed on the spool or datasheet; typically 120–250 g (cardboard lighter, plastic heavier).
How the calculator works
Weigh the spool with the remaining filament on a kitchen scale and subtract the empty spool weight. The result is the remaining amount in grams.
Length follows from weight, material density and diameter: length = mass ÷ (density × cross-section area). Everything is calculated locally in your browser.
Tip: enter the weight from your slicer – the calculator shows whether the spool is enough or whether you should open a new one to avoid a mid-print swap.
Frequently asked questions
How do I find the empty spool weight?
It is sometimes printed on the spool label. Otherwise weigh an empty spool of the same brand – typically 120 to 250 grams.
How many metres are in 1 kg of filament?
For 1.75 mm PLA (density about 1.24 g/cm³) roughly 335 metres, PETG about 330 metres, ABS about 400 metres.
Is the value exact?
No, it is an approximation: density and diameter vary slightly by manufacturer and colour.
Need to restock? Browse the filament database or use the Filament Finder.