Bambu Lab Empty Spool Weight and Filament Remaining

An empty Bambu Lab spool weighs about 242 g.

Last reviewed 29 Oct 2026

Your measurements

Weigh your spool and pick the material and brand. Everything updates as you type.

Filament

Material1.24 g/cm³

Typical density for this material. Use your filament's data sheet if it gives one.

Diameter

Most printers use 1.75 mm; some, such as Ultimaker, use 2.85 mm. It is printed on the spool label.

Spool

Spool brandEmpty 242 g

Reusable spool with cardboard core as shipped: 233–250 g reported (midpoint used). The bare reusable spool is about 208–216 g and older gen-1 spools about 251–264 g.

I weighed an empty spool myselfEmpty spools vary between batches, so your own figure is the most accurate.

Spool weight on the scale

Put the spool, with its filament, on a kitchen scale.

Rough fill level

Electricity (optional)

Printer110 W

Typical average draw, estimated. A plug-in power meter gives your printer's real figure.

Print time

Electricity price

Filament left335.3 m

PLA (Polylactic Acid) left on the spool

335.3m

= 1100.1 ft

About 100% of a 1000 g spool. Compare this with the filament length your slicer shows for the print.

Filament weight: 1000g; = 35.27 oz; Scale weight minus 242 g empty spool
Electricity for the print: $0.14; 8 h on Bambu Lab P1S (estimated draw)

The wound filament is drawn by weight left; real spools wind unevenly.

Check before you print (2)

Empty spools from this brand vary by about ±9 g, so the remaining length could be off by about ±3 m. Weigh one of your own empty spools and enter it for an exact figure.
1.24 g/cm³ is a typical density for PLA (Polylactic Acid). Brands differ by a few percent, and the length changes by the same percentage. Use the density on your filament's data sheet if you have it.

How this was calculated

Weight to length, with your numbers.

Step 1: Subtract the empty spool
W_net = W_total − W_spool
= 1242 g − 242 g
= 1000 g of filament
Bambu Lab (reusable spool, as shipped) spools are taken as 242 g (233–250 g reported). A ±9 g spread changes the answer by about 3 m.
Step 2: Cross-section of 1.75 mm filament
A = π × (d ÷ 20)²
= π × (0.0875 cm)²
= 0.024053 cm²
The diameter in millimetres is halved and converted to centimetres so the units match the density in g/cm³.
Step 3: Length from weight
L = W_net ÷ (ρ × A × 100)
= 1000 g ÷ (1.24 g/cm³ × 0.024053 cm² × 100)
= 335.3 m
Dividing by density and cross-section gives centimetres; ÷100 gives metres. A density that is 2% off makes the length 2% off.
Step 4: Electricity for the print
Cost = watts × hours ÷ 1000 × price per kWh
= 110 W × 8 h ÷ 1000 × $0.16
= $0.14
110 W is an estimated average for the Bambu Lab P1S. A plug-in power meter gives your printer's real figure.

Sources

PLA (Polylactic Acid): density
Estimated
Typical value, not from a maker's document. Measure or confirm before relying on it.
Bambu Lab (reusable spool, as shipped): empty spool weight
From source
From a published reference; brands and batches vary. Checked 23 Oct 2026.
- LayerTune: empty filament spool weights by brand (community readings) (Bambu Lab reusable spool + cardboard core, as shipped: 233–250 g (source: filamentcalcs.com)), opened 23 Oct 2026

In short

An empty Bambu Lab spool weighs about 242 g (233–250 g reported). 1242 g on the scale is a full 1 kg; 742 g is half.

The calculator starts with Bambu Lab spool and PLA selected; change the material to match your spool.

Scale reading to filament left

Each row adds the 242 g empty spool to the filament. Lengths are for 1.75 mm filament at typical densities (PLA 1.24, PETG 1.27 g/cm³).

On the scale	Filament	PLA	PETG	Of a full spool
342 g	100 g	33.5 m	32.7 m	10%
492 g	250 g	83.8 m	81.8 m	25%
742 g	500 g	167.6 m	163.7 m	50%
992 g	750 g	251.5 m	245.5 m	75%
1242 g	1000 g	335.3 m	327.4 m	100%

Bambu Lab spool facts

Item	Value
Empty spool weight	242 g (233–250 g reported)
Where the figure comes from	Community readings
Spool material	Plastic
Filament on a full spool	1000 g
Size	About 200 mm across and 67 mm wide (typical 1 kg spool size; not confirmed for Bambu Lab)

Reusable spool with cardboard core as shipped: 233–250 g reported (midpoint used). The bare reusable spool is about 208–216 g and older gen-1 spools about 251–264 g.

Empty weight, Bambu Lab spool
From source
From a published reference; brands and batches vary. Checked 23 Oct 2026.
- LayerTune: empty filament spool weights by brand (community readings) (Bambu Lab reusable spool + cardboard core, as shipped: 233–250 g (source: filamentcalcs.com)), opened 23 Oct 2026

Other brands

All 15 spools, with sources, in the empty spool weights table

Three spools of white and grey filament side by side: a cardboard spool, a plastic spool and a refill coil fitted to a reusable spool. — Left to right: a cardboard spool, a plastic spool and a refill on a reusable spool. Each weighs a different amount when empty, so the tare depends on the spool type as well as the brand.Photo: Suit, Wikimedia Commons, CC BY-SA 4.0. Credits

Worked example: a full Bambu Lab spool of PLA

The three steps behind the result, using the 242 g empty weight.

Step 1: Subtract the empty spool
W_net = W_total − W_spool
= 1242 g − 242 g
= 1000 g of filament
Bambu Lab (reusable spool, as shipped) spools are taken as 242 g (233–250 g reported). A ±9 g spread changes the answer by about 3 m.
Step 2: Cross-section of 1.75 mm filament
A = π × (d ÷ 20)²
= π × (0.0875 cm)²
= 0.024053 cm²
The diameter in millimetres is halved and converted to centimetres so the units match the density in g/cm³.
Step 3: Length from weight
L = W_net ÷ (ρ × A × 100)
= 1000 g ÷ (1.24 g/cm³ × 0.024053 cm² × 100)
= 335.3 m
Dividing by density and cross-section gives centimetres; ÷100 gives metres. A density that is 2% off makes the length 2% off.

Notes on Bambu Lab spools

Bambu Lab sells refills without a spool, so your empty weight depends on whether the cardboard core is still mounted.
Readings for the as-shipped spool range from 233 to 250 g; the bare reusable spool is lighter (208–216 g).
Weigh one of your own empty spools from this brand for an exact figure.

Bambu Lab spool: common questions

Empty weight, accuracy and the scale method.

How much does an empty Bambu Lab spool weigh?

Reusable spool with cardboard core as shipped: 233–250 g reported (midpoint used). The bare reusable spool is about 208–216 g and older gen-1 spools about 251–264 g. Weighing one of your own empties is the most accurate figure.

How do I check how much filament is left on a Bambu Lab spool?

Weigh the spool and subtract 242 g. For example, a reading of 742 g means about 500 g of filament, which is roughly 167.6 m of 1.75 mm PLA or 163.7 m of PETG.

How accurate is the empty weight?

Reported weights run from 233 g to 250 g, so a reading can be off by up to about 9 g, or roughly 3 m of PLA. Weigh one of your own empty spools to remove that error.