Filament Weight & Length Converter
Convert mass, length and volume using your filament diameter and density.
Spool Remaining Calculator
Weigh a used spool to estimate its remaining grams, length and value.
Inputs
Material Summary / Results
Enter your inputs and calculate to see the result.
Scale accuracy, empty spool weight and density affect this estimate.
Calculation method
Net grams = gross spool grams − empty spool grams. Length in meters = grams ÷ (π × (diameter in mm ÷ 2)² × density in g/cm³). Value = remaining grams ÷ purchased net grams × purchase price.
How to use this tool
Weigh the dry spool on a level scale. Use the actual empty spool weight, including any reusable hub. Reference densities are editable. Labels, moisture and scale error affect the estimate.
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Related guides
How to Calculate Filament Left on a Spool
How much usable material remains after a spool has been opened?