Empty spool weight (tare) database
An empty filament spool weighs between roughly 140 g (cardboard) and 250 g (plastic), depending on the brand. Subtract this tare from your scale reading to learn how much filament is actually left — the spool remaining calculator does this for you with these exact presets. The full table:
| Brand | Spool type | Empty weight (g) | Meters of PLA 1.75 mm you overestimate if you forget the tare |
|---|---|---|---|
| Bambu Lab | Plastic | 250 g | ~84 m |
| Fiberlogy | Plastic | 245 g | ~82 m |
| ColorFabb | Plastic | 235 g | ~79 m |
| SUNLU | Plastic | 230 g | ~77 m |
| eSUN | Plastic | 220 g | ~74 m |
| Creality | Plastic | 215 g | ~72 m |
| Prusament | Plastic | 200 g | ~67 m |
| Formfutura | Plastic | 180 g | ~60 m |
| Overture | Plastic | 160 g | ~54 m |
| ELEGOO | Plastic | 155 g | ~52 m |
| Polymaker | Cardboard | 140 g | ~47 m |
These are community-measured approximations for standard 1 kg spools (compiled by spool trackers such as filamiq and sigmafilament). Manufacturers revise spool designs without notice, so real weights drift by tens of grams between batches — weigh your own spool if the exact number matters.
How to weigh your own spool
- Wait until a spool is truly empty — or unwind the last meters.
- Put it on a kitchen scale with 1 g resolution (not a bathroom scale).
- Write the number on the next spool of the same brand, or enter it as a custom tare in the spool remaining calculator.
- Re-weigh occasionally — brands silently change spool designs, and even the detachable sides of reusable spools differ between revisions.
If you never finish spools, weigh a full one as bought and subtract the printed label weight: a 1 kg spool reading 1,220 g on the scale implies a ~220 g tare. That trick also catches underfilled spools before you start a long print.
Why the tare matters
A kitchen scale reads spool plus filament, so remaining = scale − tare. The rightmost column shows what forgetting the tare costs: at 0.335 meters per gram of 1.75 mm PLA (the same density math as the filament length to weight calculator), an unaccounted 250 g Bambu spool looks like ~84 meters of filament you do not have — roughly 30 hours of printing at typical speeds.
Frequently asked questions
How much does an empty Prusament spool weigh?
About 200 g. Prusa’s plastic spool is a typical mid-weight design — lighter than Bambu Lab’s ~250 g spool but heavier than cardboard spools such as Polymaker’s ~140 g. Weigh your own if precision matters; batches vary.
Are Bambu reusable spools lighter than cardboard?
No — the opposite. Bambu Lab’s reusable plastic spool is one of the heaviest at roughly 250 g empty, while a cardboard spool (Polymaker) is about 140 g. The plastic spool is built to survive refills; the cardboard one is built to be cheap and recyclable.
Why does the empty spool weight matter?
Because it is the only way to know how much filament is left: the scale reads spool plus filament, so subtracting the tare gives the remaining grams. Guessing the tare wrong by 50 g misjudges your remaining filament by ~17 meters of PLA — enough to ruin an overnight print.
Are these tare values exact?
No. They are community-measured approximations and manufacturers change spool designs without notice — weights can drift by tens of grams between batches and revisions. For an exact figure, weigh an empty spool of the same brand and revision yourself.
Does the tare differ between 0.5 kg and 1 kg spools?
Usually yes — smaller spools are physically smaller and lighter, and refill spools (no spool at all, just the filament coil) have a tare of zero. The values here are for standard 1 kg spools, which is what most brands sell.
Can I use a bathroom scale to weigh a spool?
Not reliably — bathroom scales are inaccurate below a few kilograms. Use a kitchen scale with 1 g resolution; they cost a few euros and double as a scale for weighing prints.