How is FDM print time calculated?

The estimator models volumetric flow rate Q = nozzle_diameter × layer_height × print_speed (mm³/s). Effective material volume is V_model × infill_fraction + surface_area × wall_thickness. Extrusion time = material_volume_mm³ / Q. A 20 % travel overhead and a 0.4 s Z-hop per layer are added. The formula matches the methodology used internally by PrusaSlicer and Cura — slicers add path-planning detail on top, so expect ±10–25 % accuracy depending on geometry complexity.

Why does my slicer give a different number?

Slicers compute the exact toolpath from a mesh: they know every perimeter length, every travel move and every retraction. This estimator works from volume and surface area alone, which avoids needing the actual STL file. For complex organic geometries the difference is typically 10–25 %; for simple prismatic parts it is often under 10 %.

How do I find model volume in PrusaSlicer?

Load your model, right-click it in the 3D view and choose Object > Model Info, or use the top menu Edit > Model Info. PrusaSlicer shows volume in cm³ and surface area in mm². Divide surface area by 100 to convert to cm².

How do I find model volume in Cura?

In the Prepare tab, select the model and open the sidebar. Scroll to Model information — it lists the volume in cm³. Surface area is not shown directly, but you can approximate it as the mesh surface area from a tool like MeshLab (Filters > Quality Measures > Compute Geometric Measures).

What infill percentage should I use?

15–20 % gyroid or honeycomb is adequate for most decorative or non-structural parts, saving significant time and material. Functional parts that take mechanical load typically need 40–60 %. Structural or load-bearing components may need 80–100 %. Halving infill from 40 % to 20 % reduces material by roughly 25–35 % and print time proportionally.

Does a larger nozzle always print faster?

Yes for the same layer height — a 0.6 mm nozzle at 0.3 mm layers moves roughly 2.25 × more material per second than a 0.4 mm nozzle at 0.2 mm layers. The trade-off is lower surface resolution on curved faces. Many users combine a 0.6 mm nozzle with 0.3 mm layers for large structural prints and switch back to 0.4 mm / 0.2 mm for detailed work.

3D Print Time & Material Estimator

An instant estimate for how long a 3D print will take and how much filament or resin it will consume — before you commit hours of machine time. Enter your model volume, infill and slicer settings and the calculator shows print duration, material mass and cost broken down into a visual time bar.

How it works

FDM (Fused Deposition Modelling)

The dominant time driver in FDM printing is extruding material. The calculation proceeds in three steps.

Step 1 — Effective material volume. Not all of the model volume is filled: infill only goes inside the shells. The estimator splits the material into two parts:

Infill volume = model volume × (infill % ÷ 100)
Shell volume = surface area × wall thickness

These are summed and capped at the total model volume.

Step 2 — Extrusion time. Volumetric flow rate Q (mm³/s) is:

Q = nozzle diameter × layer height × print speed

Extrusion time = material volume (mm³) ÷ Q

Step 3 — Overhead. A 20 % travel overhead is added for non-printing moves (a value consistent with PrusaSlicer’s internal model). Each layer change adds 0.4 s for Z-hop and carriage settle.

Total FDM time = extrusion time × 1.20 + layer count × 0.4 s

Resin (MSLA / LCD)

Resin printers expose an entire layer at once — time is independent of model volume and depends only on layer count and per-layer timing:

T = layer count × (exposure time + lift time)

Typical LCD/MSLA values are 2–4 s exposure and 6–8 s lift per layer at 0.05 mm layer height.

Material mass and cost

mass (g) = material volume (cm³) × density (g/cm³)

Density values come from published material datasheets (PLA 1.24, PETG 1.27, ABS 1.04, ASA 1.07, TPU 1.21, Nylon 1.13, Resin 1.10 g/cm³). Cost is estimated from representative retail filament prices (~$25/kg for PLA, up to ~$55/kg for Nylon).

Worked example

A 50 cm³ model with 120 cm² surface area, printed 40 mm tall in PLA with typical FDM settings (20 % infill, 0.2 mm layers, 60 mm/s, 0.4 mm nozzle, 1.2 mm walls):

Parameter	Value
Infill volume	50 × 0.20 = 10.0 cm³
Shell volume	120 × 0.12 = 14.4 cm³
Effective material	24.4 cm³ = 24 400 mm³
Flow rate Q	0.4 × 0.2 × 60 = 4.8 mm³/s
Extrusion time	24 400 ÷ 4.8 ≈ 5 083 s
Travel overhead	+20 % → 6 100 s
Layer count	40 ÷ 0.2 = 200
Z-hop total	200 × 0.4 = 80 s
Total print time	≈ 6 180 s ≈ 1 h 43 m
Material mass	24.4 × 1.24 ≈ 30.3 g
Material cost	30.3 × $0.025 ≈ $0.76

Switching to 40 % infill increases material to ~35 cm³ and pushes time to about 2 h 30 m — a useful comparison when deciding whether a part needs extra rigidity.

Quick reference — typical slicer settings

Material	Bed temp	Nozzle temp	Recommended speed
PLA	60 °C	200–215 °C	40–80 mm/s
PETG	70–85 °C	230–245 °C	30–60 mm/s
ABS	100–110 °C	230–250 °C	40–60 mm/s
ASA	100–110 °C	240–260 °C	40–60 mm/s
TPU	40–60 °C	220–240 °C	20–30 mm/s
Nylon	70–90 °C	250–270 °C	30–50 mm/s

All temperatures and speeds vary by brand and specific filament formulation — always check the manufacturer datasheet and run calibration cubes on new rolls.

Every calculation runs locally in your browser. No model data is uploaded or stored.