3D Printing Filament Length, Weight & Total Print Cost Calculator
Slicer software tells you filament length, but rarely the real dollar cost once electricity is added in. This calculator converts filament length and diameter into weight using material density, then adds material and electricity cost together for a true per-print and per-hour figure.
This print uses 74.6g of PLA and costs $1.72 total, or $0.43 per hour.
| Item | Value |
|---|---|
| Filament diameter | 1.75 mm |
| Filament length | 25.00 m |
| Volume used | 60.13 cm³ |
| Weight | 74.6 g |
| Material cost | $1.64 |
| Power used | 0.480 kWh |
| Power cost | $0.08 |
| Total cost | $1.72 |
Formula & step-by-step maths
- Diameter
- Filament diameter in mm
- Density
- Material density g/cm³
- Watts
- Printer power draw
Why filament diameter changes weight so much
A 2.85mm filament has roughly 2.65 times the cross-sectional area of 1.75mm filament for the same length, so the same slicer-reported length in metres produces far more weight and cost on thicker filament — always check which diameter your printer uses.
Material density differences matter
PETG (1.27 g/cm³) is denser than PLA (1.24) and noticeably denser than ABS (1.04), meaning the same physical print volume weighs differently and costs differently depending on material choice, even at identical spool prices.
Electricity cost is usually small but not zero
A typical desktop FDM printer draws 80-150W, and at $0.16/kWh a 6-hour print only costs $0.08-$0.14 in electricity — small per print, but worth including for shops calculating true per-unit costs across hundreds of prints.
Using this for pricing prints commercially
Add a markup multiplier (commonly 3-5x material plus labour) on top of the total cost this tool produces if you are pricing prints for sale, since raw material and power cost alone never covers printer depreciation, failed prints or your time.
Filament density and typical spool pricing
| Material | Density (g/cm³) | Typical spool price/kg | Common use |
|---|---|---|---|
| PLA | 1.24 | $18-$25 | General purpose, prototypes |
| ABS | 1.04 | $18-$28 | Functional, heat-resistant parts |
| PETG | 1.27 | $20-$30 | Outdoor, durable parts |
| TPU (flexible) | 1.21 | $25-$40 | Flexible parts, phone cases |
| Nylon | 1.14 | $35-$60 | High-strength mechanical parts |
| ASA | 1.05 | $25-$35 | UV-resistant outdoor parts |
People also ask
How do I find how many metres of filament a print used?
Your slicer software (Cura, PrusaSlicer, Bambu Studio) reports filament length and sometimes weight directly in the print preview or after slicing — copy that length figure into this calculator.
Why does my slicer's weight estimate differ slightly from this calculator?
Slicers account for infill patterns and exact geometry per layer, while this tool assumes a uniform filament cylinder; the two should be within a few percent of each other for most standard prints.
Does filament diameter tolerance affect cost accuracy?
Slightly — real filament varies ±0.02-0.05mm from nominal diameter, but this is a small enough variance that it won't meaningfully change cost estimates for planning purposes.
Should I include failed prints in cost calculations?
For personal costing, no — but if pricing commercially, build in a failure rate buffer (commonly 5-15%) on top of the material cost to cover reprints.
How much does printer depreciation add to cost per print?
A $300 printer used for 1,000 hours before major maintenance adds roughly $0.30/hour in depreciation — add this manually to the cost-per-hour figure if you want full accounting.
Is PETG really worth the extra cost over PLA?
For outdoor, high-temperature, or mechanically stressed parts, yes — PETG's added durability and heat resistance often justifies its 10-20% price premium over PLA.
What electricity rate should I use if I don't know mine?
Check a recent utility bill for your $/kWh rate, or use the US national average of roughly $0.16/kWh as a reasonable default.
Does print speed affect the cost calculation?
Only indirectly through total print hours — faster prints reduce electricity cost proportionally since power draw stays roughly constant per hour of operation.
How can I reduce filament cost per print?
Reducing infill percentage, using variable wall counts, and hollowing non-structural sections are the most effective ways to cut material weight and therefore material cost.
Can I use this calculator for resin printers?
No — resin printers are priced by volume of liquid resin (ml) rather than filament length, so this length-based calculation doesn't apply to SLA/DLP printing.
Three worked examples
Same engine, three different starting points — useful if you want to see how sensitive the answer is before you type your own numbers in.
Example 1: filament length used 19.5 m, filament type "PLA (1.24 g/cm³)"
On the lower / more conservative end. This print uses 58.2g of PLA and costs $1.36 total, or $0.34 per hour.
Example 2: filament length used 25 m, filament type "PLA (1.24 g/cm³)"
A typical middle-of-the-road setup. This print uses 74.6g of PLA and costs $1.72 total, or $0.43 per hour.
Example 3: filament length used 32.5 m, filament type "ABS (1.04 g/cm³)"
On the higher / more demanding end. This print uses 81.3g of ABS and costs $1.87 total, or $0.47 per hour.
Quick answers about the 3D Print Cost
What exactly does the 3D Print Cost work out?
Slicer software tells you filament length, but rarely the real dollar cost once electricity is added in. You enter filament type, filament diameter, filament length used and spool cost (plus 3 more optional details) and the result panel updates straight away, so you can compare two or three versions of the same question in a few seconds.
What do I need before I start?
Only 7 fields: filament type, filament diameter, filament length used, spool cost, printer power draw, print time and electricity rate. Nothing else is needed and nothing is stored.
How is it calculated — why filament diameter changes weight so much?
A 2. The same maths runs inside this page, so hand-checking the result on paper gives you the identical figure.
Why do two calculators give me different answers for 3D Print Cost?
PETG (1. Different sites pick different assumptions, so always check which method a calculator states before you trust the gap between two numbers.
What does the "Filament density and typical spool pricing" table on this page tell me?
It is the reference range this tool works against — 6 rows from "PLA" (1.24) up to "ASA" (1.05). Use it to sanity-check whether the number you just calculated sits where you expected it to.
Which filament type should I pick?
The dropdown offers 3 choices — PLA (1.24 g/cm³), ABS (1.04 g/cm³) and PETG (1.27 g/cm³). Pick the one that matches your real situation rather than the one you would like to be true; filament type usually moves the final figure more than any other single input, so it is worth running it twice with the option above and below your guess.
Do I have to press a button or reload the page to see the result?
No. 3D Print Cost runs completely inside your browser, so the moment you change a value the cards recalculate — there is no submit step, no page reload and no waiting for a server round trip. That also means it keeps working on a weak or intermittent mobile connection.
Is it free, and do you keep what I type?
It is free with no sign-up, no app install and no usage limit. Nothing you enter into 3D Print Cost leaves your device — the calculation is JavaScript running locally, so there is no upload of your figures to DrHint or anyone else.
Can I use it on a phone?
Yes — the layout stacks to a single column on small screens and the number fields open the numeric keypad on both Android and iOS. Many people bookmark this page or add it to their home screen and re-open it whenever the question comes up.
Anything to be careful about with the result?
Your slicer software (Cura, PrusaSlicer, Bambu Studio) reports filament length and sometimes weight directly in the print preview or after slicing — copy that length figure into this calculator. Treat the output as a well-grounded estimate for planning, not as a professional, legal or medical decision on its own.
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