3D Model Volume Calculator

Enter your model's shape and dimensions to instantly calculate volume, estimated filament mass, filament length, and spool usage. Supports PLA, ABS, and PETG with customizable infill percentage.

Created by Luis GonzalezLast updated: May 9, 2026

How to Use This Calculator

1
Select the Model Shape
Choose between Box, Cylinder, or Sphere to define the geometry.
2
Select the Filament Material
Choose PLA (1.24 g/cm3), ABS (1.04 g/cm3), or PETG (1.27 g/cm3). This determines mass estimation accuracy.
3
Enter Dimensions
For a box, enter length, width, and height in mm. For a cylinder, enter diameter and height. For a sphere, enter diameter only.
4
Set the Infill Percentage
Enter the interior fill density (0-100%). 20% is standard for most parts; higher infill means more material and stronger prints.
5
Review Your Results
The calculator displays six results: Solid Volume (cm3), Estimated Mass (g), Filament Length (m), Effective Volume (cm3), Spool Usage (%), and Print Density (%).

Example Calculation

A maker wants to estimate filament usage for a 50 x 50 x 50 mm box printed in PLA at 20% infill.

Shape

Box

Material

PLA (1.24 g/cm3)

Length

50 mm

Width

50 mm

Height

50 mm

Infill Percentage

20 %

Results

Solid Volume

125.00 cm3, Estimated Mass: 55.8 g, Filament Length: 18.71 m, Effective Volume: 45.00 cm3, Spool Usage: 5.6%, Print Density: 36.0%

Tips

Infill Dramatically Affects Usage

Going from 20% to 100% infill doesn't just 5x the material — the shell fraction means effective fill goes from 36% to 100%, roughly a 2.8x increase in mass and filament for the same outer shape.

Spool Planning

A standard spool is 1 kg. At 5.6% per 50mm cube, you could print about 17 cubes from one spool. Use this to plan material purchases for batch jobs.

Material Choice Matters

The same 50mm cube at 20% infill uses 55.8g in PLA but only 46.8g in ABS (density 1.04 vs 1.24). PETG at 1.27 g/cm3 uses slightly more than PLA.

Understanding the Space a 3D Model Occupies

Accurately determining the volume of a 3D model is essential for estimating filament consumption, print weight, and spool planning. This calculator goes beyond raw volume to provide estimated mass in grams, filament length in meters, and spool usage percentage — the practical numbers you need to plan a print job. A typical 50mm cube at 20% infill uses about 55.8g of PLA and 18.71 meters of filament.

The Mathematical Foundations of Volume and Material Estimation

The calculator first computes solid volume from geometry, then applies infill and shell fractions to estimate actual material usage:

solid_volume_mm3 (box) = length × width × height
solid_volume_mm3 (cylinder) = pi × (diameter / 2)^2 × height
solid_volume_mm3 (sphere) = (4/3) × pi × (diameter / 2)^3
solid_volume_cm3 = solid_volume_mm3 / 1000

effective_fraction = 0.2 + (1 - 0.2) × (infill% / 100)
effective_volume_cm3 = solid_volume_cm3 × effective_fraction

mass_g = effective_volume_cm3 × density
filament_length_m = (effective_volume_cm3 / (pi × 0.0875^2)) / 100
spool_usage_% = (mass_g / 1000) × 100
print_density_% = effective_fraction × 100

Where 0.2 is the shell fraction (20% of the part is solid wall), density is material-specific (PLA=1.24, ABS=1.04, PETG=1.27 g/cm3), and filament radius is 0.0875 cm (1.75mm diameter).

💡 While calculating model dimensions, you might encounter other numerical challenges. Our 24 Game Solver can help sharpen your mental math skills for quick calculations.

Estimating Filament for a Box Print

Consider a maker printing a 50 x 50 x 50 mm box in PLA at 20% infill using a standard 1.75mm filament.

Solid volume: 50 × 50 × 50 = 125,000 mm3 = 125.00 cm3
Effective fraction: 0.2 + 0.8 × 0.2 = 0.36 (36.0%)
Effective volume: 125.00 × 0.36 = 45.00 cm3
Estimated mass: 45.00 × 1.24 = 55.8 g (PLA at 20% infill)
Filament length: (45.00 / (pi × 0.0875^2)) / 100 = 45.00 / 0.02405 / 100 = 18.71 m
Spool usage: (55.8 / 1000) × 100 = 5.6% of a 1 kg spool (Small print)
Print density: 36.0% — Shell + 20% interior infill

The print will consume approximately 55.8g of PLA (18.71m of filament), using 5.6% of a standard spool.

💡 Understanding variations in model size and material properties is key. To analyze how specific dimensions might deviate from a target, our Standard Deviation Z-Score Table can help assess statistical significance.

Practical Application Context

In 3D printing services, volume and mass directly determine material cost. At $25/kg for PLA, that 55.8g cube costs about $1.40 in material. For batch production, spool planning is critical — knowing each unit uses 5.6% of a spool means you need 6 spools for 100 units. In engineering prototyping, comparing materials matters: the same geometry in ABS weighs 46.8g vs 55.8g in PLA, affecting functional testing of weight-sensitive parts. The filament length estimate also helps verify slicer estimates and detect potential issues with very long prints that might exceed a partial spool.

What model volume results look like in practice

Common reference points for 3D printed objects:

Small parts (keychains, clips): 5-20 cm3, 2-9g PLA, under 1% spool
Medium parts (phone cases, brackets): 50-150 cm3, 20-70g PLA, 2-7% spool
Large parts (vases, enclosures): 200-1000 cm3, 90-450g PLA, 9-45% spool
Very large parts (helmets, panels): 1000+ cm3, 450g+ PLA, 45%+ spool

These ranges assume 20% infill. At 100% infill, multiply mass by approximately 2.8x.

Frequently Asked Questions

Why is calculating 3D model volume important?

Volume determines material consumption, print cost, and time. A 50mm PLA cube at 20% infill uses 55.8g of filament (18.71m of 1.75mm filament), which is 5.6% of a standard 1kg spool.

What does 'Effective Volume' mean?

Effective volume accounts for the infill pattern. At 20% infill, the effective fill fraction is 36% (20% shell + 80% interior at 20% fill). So a 125 cm3 bounding box has 45 cm3 of actual material volume.

How is filament length calculated?

The calculator divides effective volume by the cross-sectional area of 1.75mm filament (pi x 0.0875^2 cm2 = 0.02405 cm2). For 45 cm3 effective volume: 45 / 0.02405 = 1871 cm = 18.71 m.

What does Print Density represent?

Print Density shows the overall material fraction: shell (20%) plus infill of the interior. At 20% infill it's 36%, meaning the print is 36% solid material and 64% air. At 100% infill it would be 100% (fully solid).