Will this spool finish the job?
Subtract real tare, then budget the sliced job, extra losses and reserve.
Your measurements
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Illustrative starting values. Replace them with your measurements. A calculation is not a physical print test or a quality guarantee.
How to use it
Weigh the complete spool, including anything present in your tare measurement. Use the actual empty spool mass—not the advertised filament net weight. Include supports and purge already counted by the slicer in the job field. Put only additional, uncounted loss in the extra field.
The arithmetic
remaining = gross − tare; balance = remaining − job − extra loss − reserve
A 600 g spool with a 220 g tare holds 380 g. A 250 g job + 20 g extra loss + 30 g reserve requires 300 g, leaving an 80 g budget margin.
Know the limits
A positive margin is an arithmetic budget, not a guarantee that the print will finish. Tare varies between spools; moisture, scale error, tangles and slicer assumptions matter. Reserve is withheld once, not consumed twice. Gross below tare is rejected, never shown as negative remaining filament.
Inputs must be finite and non-negative; measured dimensions, density and calibration references must be positive. Out-of-range inputs clear the result rather than leaving a stale answer.
Method, sources & input boundaries →