How print time is estimated
A printer lays down plastic at a volumetric rate: how many cubic millimetres leave the nozzle each second. Divide the part’s volume by that rate and you get the time spent extruding. Real prints also spend time travelling, accelerating and slowing for small layers, which the efficiency figure covers.
This is an estimate for planning. Your slicer simulates every move and gives the most accurate time; use this page to compare settings quickly.
Worked example
A 50 g PLA part printed at 60 mm/s with 0.2 mm layers and a 0.45 mm line width:
- Volume: 50 ÷ 1.24 × 1000
- 40,323 mm³
- Flow: 60 × 0.2 × 0.45
- 5.4 mm³/s
- Pure extrusion: 40,323 ÷ 5.4
- 2 h 4 min
- At 60% efficiency
- 3 h 27 min
What actually makes prints faster
| Change | Effect on flow | Trade-off |
|---|---|---|
| 0.2 → 0.28 mm layers | +40% | Visible layer lines |
| 0.4 → 0.6 mm nozzle | About +45% (0.45 → 0.65 mm lines) | Less fine detail |
| 60 → 100 mm/s | +67% | Needs a hotend that can melt fast enough |
| Infill 20% → 10% | Less volume to print | Weaker parts |
Speed only helps if the hotend can melt plastic fast enough. Many standard hotends top out around 10–15 mm³/s with PLA; above that, prints under-extrude. High-flow hotends go much higher. The calculator warns you when the settings ask for more than 15 mm³/s.
Frequently asked questions
Why does my slicer show a longer time than the printer takes?
Some slicers use simple motion limits that differ from your printer’s firmware settings. Setting the same acceleration and jerk or junction deviation values in the slicer as in the firmware makes estimates more accurate.
How long does it take to 3D print 1 kg of filament?
At 5–6 mm³/s and typical efficiency, about 2 to 3 days of printing. A fast printer at 15–20 mm³/s can get through 1 kg in under a day.
Does infill change print time?
Yes, because it changes the volume printed. Use the part weight calculator to see the weight at a new infill, then enter it here.
What efficiency should I use?
Around 50–60% for most home printers and small parts. Large, simple parts with long straight lines can reach 70% or more; tiny detailed parts can drop below 40%.
Last reviewed October 2026. See how we calculate.