3D Printer Calibration & Design Tools
A 3D printer is a CNC machine with a hot nozzle, and the same rules apply: calibrate the machine first, then design the part for the process. These free tools cover both halves, and every one runs in your browser with nothing to install.
Start with calibration. The steps per mm calculator works out Marlin M92 values and Klipper rotation_distance for belts, lead screws and geared extruders, and corrects them from a measured move. Then tune retraction and linear or pressure advance with a test tower, check your bed with the mesh visualizer, and turn Klipper input shaper results into a printer.cfg block.
Design for printing is where machinists feel at home. Printed holes come out small and pins come out large, so the hole compensation calculator gives the CAD size for press, slip and running fits. The heat-set insert chart gives hole sizes for brass inserts, the shrinkage tool works out slicer scale factors from a measured test part, and the strength estimator shows why more walls usually beat more infill.
Two makers turn ideas into STL files: Image to Lithophane builds flat, curved and lamp-shade lithophanes from a photo, and Text & Sign to STL makes name plates, signs and keyring tags.
Where a tool gives a firmware setting it shows both the Marlin command and the Klipper config line. Change one setting at a time and print a test after each change.
Start here
Calculators
Free, browser-based and no sign-up needed.
Calibrate the printer
Steps per mm Calculator
Marlin M92 steps/mm and Klipper rotation_distance for belts, lead screws and geared extruders, plus e-steps calibration.
Open Calculator: Steps per mm CalculatorRetraction Settings
Starting retraction distance and speed for direct drive or Bowden, plus a test tower plan with Klipper and Marlin commands.
Open Calculator: Retraction SettingsLinear / Pressure Advance
Marlin M900 K and Klipper pressure_advance from a tuning tower or line pattern, with an optional test pattern G-code.
Open Calculator: Linear / Pressure AdvanceBed Mesh Visualizer
Paste Marlin, Klipper or Prusa bed mesh output for a 3D view, heat map, flatness and bed-screw turns.
Open Calculator: Bed Mesh VisualizerInput Shaper Explainer
Explain Klipper SHAPER_CALIBRATE results and get printer.cfg, max_accel and Marlin M593 settings.
Open Calculator: Input Shaper ExplainerDesign parts for printing
3D Print Hole Compensation
CAD sizes for printed holes and pins: press, slip or running fits, STL facet loss and test-plate calibration.
Open Calculator: 3D Print Hole CompensationHeat-Set Insert Hole Size
Hole size, depth and boss for brass heat-set inserts M2–M8 and #2-56–1/4-20, plus screw pilot and clearance holes.
Open Calculator: Heat-Set Insert Hole SizePrint Shrinkage & Scale
Per-axis scale % from a measured test print for Cura, PrusaSlicer and Orca, typical shrinkage, and steps vs shrinkage.
Open Calculator: Print Shrinkage & ScalePrint Strength vs Infill
Compare walls, top layers and infill: filament grams and metres, a relative strength index and time. Walls beat infill.
Open Calculator: Print Strength vs InfillMake STL files
Image to Lithophane STL
Turn a photo into a watertight lithophane STL: flat, curved or lamp shade, with frame, stand and backlit preview.
Open Calculator: Image to Lithophane STLText & Sign to STL
Make raised or engraved text signs, name plates and keyring tags as watertight STL, plus DXF outlines.
Open Calculator: Text & Sign to STLReference charts
Frequently asked questions
- How do I calibrate e-steps on a 3D printer?
- Mark the filament 120 mm above the extruder, extrude 100 mm slowly with the hotend at printing temperature, and measure what is left to the mark. New steps per mm = old steps per mm × 100 ÷ the length actually extruded. In Klipper the rotation_distance changes the other way: new = old × actual ÷ requested.
- Why are 3D printed holes too small?
- The slicer turns a circle into flat facets, and the extruded line squashes inward on curves, so holes print undersize and pins print oversize. Model holes a little larger, or print a test plate and let the hole compensation calculator fit a correction.
- What size hole do I need for an M3 heat-set insert?
- For the common M3 × 5.7 mm brass insert with a 4.6 mm outside diameter, a 4.0 mm hole about 6.7 mm deep is typical. Always check your insert maker's datasheet, because sizes vary between brands.
- Should I use more walls or more infill for strength?
- For most parts, more walls. Bending and twisting loads are carried mostly by the outer skin, so adding walls raises strength faster per gram than raising infill. The strength estimator compares the options.