A filament calculator converts between 3D printer filament weight, length, and volume using material density and filament diameter. Whether you need to know how many meters remain on a spool, estimate if you have enough filament for a print, or compare cost per meter across brands, this tool handles the math instantly in your browser.
Filament Settings
Adjust manually for custom or blended filaments
Weight to Length
Cost per Meter
Material Density Reference
| Material | Density (g/cm³) | 1kg @ 1.75mm | 1kg @ 2.85mm |
|---|
How to Use This Filament Calculator
Every 3D printing project starts with the same question: do I have enough filament? Whether you are planning a long print, comparing spool prices, or trying to use up a partially spent spool, this filament calculator gives you precise conversions between weight, length, and volume for any material and diameter.
Step 1: Choose Your Filament Settings
Start by selecting your filament diameter: 1.75 mm (the most common for consumer printers) or 2.85 mm (used by some professional machines). Then pick a material preset such as PLA, PETG, ABS, TPU, Nylon, ASA, HIPS, or Polycarbonate. Each preset fills in the correct density automatically. If you are using a specialty blend, you can override the density manually.
Step 2: Convert Weight to Length (or Vice Versa)
In the Weight to Length tab, enter the filament weight in grams or kilograms and the calculator instantly shows the equivalent length in meters and feet. This is useful when your slicer reports material usage by weight and you want to know the length, or when comparing spool sizes. Switch to the Length to Weight tab to do the reverse calculation. The formula used is length = weight / (density × π × r²), where r is the filament radius.
Step 3: Estimate Remaining Filament on a Spool
Switch to the Remaining Spool tab when you have a partially used spool. Place your spool on a kitchen or postal scale to get its current total weight. Enter that weight along with the empty spool weight (typically 150 to 250 grams, often printed on the label). The calculator subtracts the reel weight and shows you remaining grams, meters, and a percentage bar so you can tell at a glance how much filament is left.
Step 4: Check Print Feasibility
After estimating remaining filament, enter the weight your slicer estimates for your next print. The calculator compares the two values and tells you whether you have enough filament or how many grams you are short. This prevents the frustration of running out mid-print and wasting time and material.
Step 5: Calculate Cost per Meter
Enter your spool price and net weight in the cost section to see cost per meter and cost per gram. This makes it easy to compare value across different brands, materials, and spool sizes. A cheaper price tag does not always mean better value when spool weights differ. All calculations happen locally in your browser with no data sent anywhere.
FAQ
Is this filament calculator free to use?
Yes, this filament calculator is completely free with no limits. You can convert between weight, length, and volume as many times as you need. There is no signup, no premium tier, and no restrictions.
Is my data private and secure?
Absolutely. All calculations happen entirely in your browser using JavaScript. No filament data, spool weights, or any other information is ever sent to a server. Your data stays on your device.
How do I find the weight of my remaining filament?
Weigh your spool on a kitchen scale or postal scale. Then subtract the empty spool weight (typically 150-250g depending on the brand) to get the net filament weight. Many spool manufacturers print the empty spool weight on the label.
What is the density of PLA filament?
PLA (Polylactic Acid) has a density of approximately 1.24 g/cm3. This is the most common 3D printing filament and is used as the default in most filament calculators. Other materials like PETG (1.27 g/cm3) and ABS (1.04 g/cm3) have different densities.
What is the difference between 1.75mm and 2.85mm filament?
These are the two standard filament diameters. 1.75mm is the most common and works with the majority of consumer 3D printers. 2.85mm (sometimes labeled 3mm) is used by some professional printers. The same weight of 2.85mm filament yields shorter lengths because the cross-section is larger.
How much filament is on a standard spool?
The most common spool size is 1 kg (1000g) of net filament. Other standard sizes include 250g, 500g, 2.5kg, and 5kg. A 1 kg spool of 1.75mm PLA contains approximately 335 meters of filament. The total spool weight includes the plastic reel, typically adding 150-250g.
How accurate is the filament length calculation?
The calculation uses the standard formula: length = weight / (density x pi x radius squared). It is mathematically exact for the given inputs. Real-world accuracy depends on your filament's actual diameter tolerance and density, which can vary slightly between manufacturers and even between batches.
Can I calculate cost per meter of filament?
Yes, enter your spool price in the cost section and the calculator will show cost per meter and cost per gram. This helps you compare value across different filament brands and materials, especially when spool sizes differ.