Filament Spool Planner
Plan every gram of your 3D printing filament: convert filament weight to length and length to weight, translate grams into filament cost, check whether the spool on your desk will finish your print, and track your whole spool inventory in one place. This filament usage calculator — a filament weight calculator, filament length calculator and filament consumption calculator in one — works for 1.75 mm and 2.85 mm filament, PLA, PETG, ABS, ASA, TPU, Nylon and more — and answers the questions makers actually ask: how much filament does a 3D print use, how long is 1 kg of PLA filament, how many prints per spool, and how much filament is left on my spool?
Filament weight ↔ length ↔ cost converter
A filament cost calculator per gram and filament weight to cost estimator: enter any amount and get weight, length and price at your spool's price per kg.
Cost is formatting-only in the selected currency — nothing is converted.
Results
Will this spool finish my print?
This 3D print weight calculator turns your slicer's gram estimate into a plain answer. Weigh the whole spool on a kitchen scale (grams), subtract the empty-spool weight, and compare against the slicer estimate below.
Breakdown
Spool inventory
Saved in this browser only (localStorage). Add each spool once, weigh it when you want an update — totals show your combined net filament, total filament spool length and material value.
Your spools
Inventory totals
Filament length reference — meters per kilogram
Grams per meter = density × π × (diameter/2)². Meters per kg = 1000 ÷ g/m. Headline: 1 kg PLA filament length is 335 m (1.75 mm) or 126 m (2.85 mm). To convert filament length to grams, multiply meters by the g/m column. Densities are typical published values; brand and color vary a few percent.
Empty-spool (tare) weight database
Community-reported approximations (±20 g). Weigh your own empty spool once for exact results — enter that value manually in the finish check or inventory.
Why a safety margin?
Filament mass per meter scales with the square of the diameter: ±0.05 mm tolerance on 1.75 mm filament changes the mass per meter by about ±6%. Slicer estimates assume nominal diameter and density, so a 10% safety margin in the finish check absorbs real-world variance. When a spool is nearly empty and the print is critical, weigh the spool instead of guessing.