Filament cost calculator: price per gram, per meter and per print

The formula

Filament cost is the spool’s price spread over its grams, times the grams the print uses.

landed price  = spool price + shipping and tax per spool
cost per gram = landed price / net grams on the spool
cost per kg   = cost per gram x 1000
cost per m    = cost per gram x grams per meter
grams per m   = density x π x diameter² / 4
print cost    = grams used x (1 + extra share) x cost per gram

Net grams means the filament alone. A “1 kg” spool holds 1,000 g of filament, and the reel weighs extra. The extra share covers filament the slicer’s part figure leaves out, such as purge and brims. The calculator defaults to a $19.99, 1,000 g spool of PLA and a 100 g print. Polymaker’s US store lists PolyLite PLA 1 kg at that price.

How much does filament cost per gram?

Most 1 kg spools of PLA cost 1.6 to 2 cents per gram. On their US stores in October 2026, Bambu Lab and Polymaker listed 1 kg of PLA at $15.99 to $19.99. Engineering filaments cost more: Bambu Lab’s PA6-CF is $79.99 per kg, 8 cents a gram. Your own figure is the spool’s price divided by its net grams.

US spool prices, October 2026

These are the prices each maker’s US store listed on October 8, 2026, before shipping and tax. They change often, so enter your own receipt in the calculator.

Filament	Net weight	Price	Per kg	Per gram
Bambu Lab PLA Basic, refill (no reel)	1 kg	$15.99	$15.99	1.6¢
Bambu Lab PLA Basic, with spool	1 kg	$18.99	$18.99	1.9¢
Polymaker PolyLite PLA	1 kg	$19.99	$19.99	2.0¢
Polymaker PolyLite PLA	3 kg	$49.99	$16.66	1.7¢
Polymaker PolyLite PLA	5 kg	$79.99	$16.00	1.6¢
Polymaker PolyMax PLA	0.75 kg	$29.99	$39.99	4.0¢
Bambu Lab PETG Basic, with spool	1 kg	$16.99	$16.99	1.7¢
Bambu Lab PA6-CF	0.5 kg	$42.99	$85.98	8.6¢
Bambu Lab PA6-CF	1 kg	$79.99	$79.99	8.0¢

Cost per meter

Slicers that report meters need one more number: how many grams a meter of that filament weighs. For 1.75 mm PLA at 1.24 g/cm³, the density on Bambu Lab’s PLA Basic data sheet, one meter weighs 2.98 g. At 2 cents a gram that is 6.0 cents a meter. The calculator takes the density from the material you pick, so ABS or nylon gets its own figure.

How do you calculate the filament cost of a print?

Divide the spool’s price, plus any shipping and tax, by its net grams to get the cost per gram. Then multiply by the grams your slicer reports for the print. A 100 g part from a $19.99, 1,000 g spool uses $2.00 of filament. If your slicer leaves out purge or brims, add a share for them.

Worked example with the defaults

1. Cost per gram: $19.99 / 1,000 g = $0.020.
2. Filament cost: 100 g x $0.020 = $2.00.
3. Cost per kg: $19.99. Cost per meter: 2.98 g x $0.020 = $0.060.
4. Prints per spool: 1,000 / 100 = 10.

Add 10% for a purge tower and brim and the same print uses 110 g, costing $2.20. The spool then covers 9 whole prints.

When the slicer gives meters

Switch “Slicer reports” to meters. The calculator turns meters into grams with the diameter and density, then prices the grams. The default 33.5 m of 1.75 mm PLA is 99.9 g, the same $2.00. For more on the conversion and on checking how much is left on a spool, see the filament length to weight converter.

Shipping and tax

Add shipping and sales tax per spool. A $10 shipping charge on a two-spool order adds $5 to each spool. On a $19.99 spool that raises the cost per gram from 2.0 to 2.5 cents, a quarter more on every print.

Is a bigger filament spool cheaper per kilogram?

Usually, yes. Polymaker lists PolyLite PLA at $19.99 for 1 kg, $49.99 for 3 kg and $79.99 for 5 kg, so the 5 kg spool costs 20% less per kilogram. Small spools go the other way. Bambu Lab’s PA6-CF costs $85.98 per kg in 0.5 kg spools and $79.99 per kg in 1 kg spools.

Refills cost less because the reel is not included

Bambu Lab sells PLA Basic for $18.99 with a spool and $15.99 as a refill that goes on a reel you already own. The $3 gap is 16% of the spooled price. The company sells the reusable reel on its own for $11.99 and lists it at 250 g. A refill saves money only when you already own a reusable reel.

What a bigger spool costs you besides the price

A 5 kg spool sits on its reel far longer than a 1 kg one. Nylon, TPU and PETG absorb water from the air, so a bulk spool that sits for months needs a dry box. The wet filament checklist shows the signs of a spool that needs drying. Big reels are also heavier: Polymaker lists 370 g for its 2 kg cardboard spool and 819 g for its 5 kg plastic spool. Check that your spool holder and feed path can take that weight.

Comparing spools in the calculator

Enter up to two more spools under “Compare other spools”, each with its delivered price and net weight. The calculator puts all three on a per-kilogram basis and names the cheapest. It also shows how much the cheapest saves on the print you entered. For example, a 5 kg spool at $79.99 against the default 1 kg at $19.99 saves $3.99 per kg, or 40 cents on a 100 g print.

Filament is only part of a print’s cost

Filament is often the biggest single cost of a hobby print, but not the whole cost. Electricity, printer wear, failed attempts and your time add to it. For a seller, those lines often cost more than the plastic. The print cost calculator adds those lines to the filament figure and suggests a selling price. For prints that change colors, the multi-color waste calculator estimates the purge filament the slicer’s part figure may leave out.