Empty spool weights
Bambu Lab empty spool weight: reusable spool, refill core, cardboard
Bambu Lab does not publish a clear empty weight for its spools. Its store lists the reusable spool at 250 g but does not say whether that is the empty spool or the packed item. The numbers below come from people who weighed their own spools, and each row links to where they came from.
What matters most is what is on your scale. With a refill mounted, the reusable plastic spool plus the refill's cardboard core measured 245 to 260 g. The calculator below starts at 253 g, the middle of those measurements.
Bambu Lab spool weights at a glance
| Spool and what is on the scale | Empty weight (g) | Evidence |
|---|---|---|
Reusable spool + refill core Plastic reusable spool with the refill's cardboard core inside | ~253 (245-260) g empty | User measurements Five spools weighed by three people: 245, 253, 253, 255 and 260 g, across white, transparent and light-grey spools. |
Reusable spool, bare Plastic reusable spool only, no cardboard core | 208-216 g empty | User measurements Four people's measurements: 208 g (one person, four spools), 210 g, 212 g and 216 g (two people, one of whom did not say whether the core was on). Sources disagree on which color is the high-temperature version, so we do not split by rating. |
Refill cardboard core alone The cardboard ring a refill is wound on | ~37 (37-38) g empty | User measurements One person's measurement. Another reported 35 g but later said their scale had problems. |
Cardboard spool (PPA-CF) Empty all-cardboard spool from a 0.75 kg PPA-CF roll | ~196 (195-196) g empty | User measurements Two separate measurements of PPA-CF spools. Other Bambu cardboard-spool products were not measured, and cardboard can shift about 6 g with humidity. |
Bambu store listing, reusable spool Not stated: empty spool or packed item | 250 g empty | Manufacturer Bambu's store lists "Weight 250 g" for both temperature versions without saying what is weighed. Measured bare spools are lighter, so treat this as a shipping-style figure. |
“Manufacturer” means the brand publishes the number. “User measurements” means people weighed their own spools and posted the result, so your spool can differ. The exact answer takes one minute: weigh an empty spool of the type you use, write the number on it, and pick Custom in the calculator from then on.
What a wrong tare does to your answer
Every gram of tare error moves the remaining-filament answer by the same gram. Say the scale reads 300 g and you are unsure whether the tare is 200 g or 225 g. One gives 100 g of filament left, the other 75 g. For an 80 g print, that is the difference between 20 g to spare and 5 g short. When a print is close, weigh an empty spool of the same type before you trust any preset.
How to weigh it right
- Take the spool off the printer or out of the AMS. Anything supporting the spool skews the reading.
- Use a kitchen scale on a flat surface. Gram resolution is plenty; you do not need a lab scale.
- Enter the total weight above, pick the matching spool type, and read off grams remaining. The result updates as you type.
Frequently asked
- Why doesn't Bambu Lab print the spool weight on the spool?
- Bambu has not said, and owners keep asking on its forum. Until it does, weigh one empty spool of each type you own and write the number on it. The presets get you close, but your own measurement is exact.
- How much does the refill cardboard core weigh on its own?
- About 37 g in the most careful measurement we found (37 to 38 g). Owners measured the reusable spool at 208 to 216 g bare and 245 to 260 g with a refill mounted; the core is most of the difference, and individual spools and cores vary. If you weigh a spool with a refill on it, use the with-core figure.
- Can I weigh the spool while it's in the AMS?
- No, take it out. The AMS rollers support the spool, so a reading taken while it is docked is not its weight. Pull the spool, weigh it on a kitchen scale, put it back.
- Do the high-temp and low-temp reusable spools weigh the same?
- Close enough that the measurements do not separate them: every bare measurement we could confirm landed between 208 and 216 g. The rating matters for drying instead. Bambu's datasheets list PLA and PETG on an ABS spool rated to 70 °C, and ABS, ASA, PC, TPU and nylon on a PC + ABS spool rated to 90 °C.
Where these numbers come from
Each row above names its evidence. Sources were last checked October 10, 2026. Spool designs change without notice, so if your spool disagrees, trust your scale over any table, including this one.
- Bambu Lab forum: measured spool and core weights
- Bambu Lab forum: filament spool weight thread
- Empty Spool Weight Catalog and its comments (Printables)
- Bambu Lab forum: refill weight and scale issues
- Bambu Lab forum: PPA-CF cardboard spool weight
- Bambu Lab forum: calculating the remains on a spool
- Bambu Lab store: reusable spool
- Bambu PLA Basic datasheet (spool material and 70 °C rating)
- Bambu ABS datasheet (spool material and 90 °C rating)
Correction note: October 10, 2026: the refill-core preset changed from 233 g to 253 g, and the cardboard-spool preset from 205 g to 196 g, after we traced each number to its source. The old 233 g assumed a 25 g core; measured cores are 37 to 38 g, so it overstated remaining filament by about 20 g. A 250 to 264 g first-generation range, whose 264 g upper end we could not trace, was removed.