Filament Cost Calculator
Material cost only, but built for how you actually print: add every color or spool in a print, apply a waste factor that matches your material, and see cost per gram to compare spools fairly.
Need the full picture, electricity, machine wear, labor, and a suggested selling price? Use the 3D Printing Price Calculator instead. This page stops at material cost.
Calculator
Estimates only. Actual waste varies by printer, settings, and filament condition.
How much filament do I have left?
Weigh your partial spool on a kitchen scale, enter the numbers below, and see exactly how much filament, and how much it's worth, is still on there.
One-time calculation, this page doesn't save or track inventory between visits.
How it works
- Enter each filament used. One row for a single-color print, add rows for every color or material in a multi-color print.
- Pick a material to get a sensible starting waste factor, or set your own.
- Check the AMS/multi-color box if this is a tool-change print, the tip will remind you purge waste runs much higher than a single-color print.
- Read the result. Total cost, cost before waste, the waste amount by itself, blended cost per gram, and prints-per-spool for each filament.
Worked examples
Single spool: a $20 spool (1000g) with 45g used and a 5% waste factor comes to $0.90 before waste, $0.95 total, and $0.021 per gram, with 22 prints available from that spool at that usage.
Multi-color AMS print: 32g of black PLA ($20/1000g), 8g of white PLA ($22/1000g), and 5g of brass PLA ($24/1000g) comes to $0.94 before waste. With a 40% purge-waste factor (typical for a 3-color tool-change print), that becomes $1.31 total, a blended $0.029 per gram, meaningfully more than the single-color math alone would suggest.
Filament remaining: a spool that weighs 650g on the scale, with a 230g empty-spool tare, has 420g of filament left. At $20/1000g, that's $8.40 of material still on the spool, enough for about 9 more prints at 45g each.
The waste factor here is not the same thing as the failure buffer on the price calculator. This one covers the small, routine loss every print has (purge, priming, skirts, brims). A fully failed print is a separate, larger cost, that's what the price calculator's failure buffer is for.
Related guides
Frequently asked questions
What's the difference between this and the price calculator?
This page covers material cost only, useful for multi-color prints or comparing spools. The price calculator adds electricity, machine wear, labor, and a suggested selling price on top.
What is the waste factor, and why isn't it zero?
Every print loses a little filament to purging, priming, skirts, and brims, even a clean, successful print. The waste factor accounts for that routine loss. It's separate from the failure buffer on the price calculator, which covers entire failed prints.
Why is AMS or multi-color waste so much higher?
Every color change on a tool-change system usually means purging the old color out of the nozzle into a purge tower before the new color prints cleanly. On prints with a lot of color changes, that purge tower can use 30–60% of the total filament consumed.
How do I find grams used?
Your slicer (Cura, PrusaSlicer, OrcaSlicer, Bambu Studio) reports estimated filament weight per color after slicing. Use that number for each row.
Why does spool weight matter if the price looks the same?
The "1kg" on a spool label almost always means 1000g of filament by itself, the empty spool adds extra weight on top. The exception to watch for is a handful of brands that sell noticeably less than 1000g under "1kg" positioning, Prusament ships 970g and some PETG lines run as low as 750g. Always check the actual spool weight rather than assuming, see our filament cost per gram guide for more on this.
How do I find my spool's tare (empty) weight?
Weigh a spool once it's completely empty, most brands ship empty spools weighing somewhere between 130g and 300g. The brand presets above are typical values, use your own measured tare for an exact number if you have one.
About the author
Cedrick Reese founded Ready Utilities to build free, user-friendly online tools that simplify everyday tasks. His path started in the early 2000s with affiliate marketing and niche site development, which grew into a passion for practical digital utilities and calculators. After retiring from the military, he earned a Computer Systems Technician certificate from UEI College, completed Electro-Mechanical Technologies at Tulsa Welding School, and finished the Carpentry program at Florida State College at Jacksonville. Today he combines that technical background with traditional woodworking, gardening, and building tools like this one. Read more about Ready Utilities.
This calculator provides cost estimates for informational purposes and isn't a substitute for your own bookkeeping. Some links on this site may be affiliate links; see our affiliate disclosure.