When this helps
Compare two spool sizes on price per kilogram of filament. Start with Spool A price; this calculator reports B price difference versus A.
Tools · Costs
Compare spool prices
Compare two spool sizes on price per kilogram of filament.
Results
- Spool A price per kg
- 25 currency / kg
- Spool B price per kg
- 24 currency / kg
- B price difference versus A
- -4 %
Method
Price per kg = price × 1000 ÷ filament grams. Difference = (B − A) ÷ A × 100%.
Worked example
Example inputs
- Spool A price
- 25 currency units
- Spool A filament weight
- 1000 g
- Spool B price
- 18 currency units
- Spool B filament weight
- 750 g
Calculated outputs
- Spool A price per kg
- 25 currency / kg
- Spool B price per kg
- 24 currency / kg
- B price difference versus A
- -4 %
How to read the result
With these example inputs, B price difference versus A is -4 %. Use that value for the setting or decision named above, and read the other outputs as supporting checks.
Common mistake
Do not leave Spool A price at the example value of 25 currency units unless it matches your own measurement.
Assumptions and limits
A positive difference means B costs more per kg. Delivery, material quality and the empty spool weight are excluded.