A 3D print shrinkage calculator helps you determine the exact scale factor needed to compensate for material shrinkage during 3D printing. Thermoplastics contract as they cool from melting temperature to room temperature, causing finished parts to come out slightly smaller than designed. By scaling your model up before printing, you can achieve precise final dimensions every time.
Material
Shrinkage rate: 1.50%
Desired Dimensions (mm)
Leave Y and Z at 0 for single-dimension calculation
Scale Factor
Scaled Dimensions
Material Comparison
Mid-range shrinkage for each material
Measure Your Print
Print a calibration cube (20mm is standard) and measure the result to find your actual shrinkage rate.
Actual Shrinkage
Calibration Tips
- Print a 20mm cube at your normal settings
- Let it cool completely before measuring
- Use digital calipers for accuracy
- Measure at the center, not edges
- Print 2-3 cubes and average the results
Tips to Reduce Shrinkage
Material Shrinkage Reference
| Material | Shrinkage Range | Enclosure Needed | Notes |
|---|---|---|---|
| PLA | 0.3 - 0.5% | No | Lowest shrinkage, easiest to print |
| PETG | 0.5 - 1.0% | No | Good balance of strength and accuracy |
| ABS | 1.0 - 2.0% | Recommended | Prone to warping without enclosure |
| Nylon | 1.5 - 3.0% | Required | Highest shrinkage, also absorbs moisture |
| ASA | 0.5 - 1.0% | Recommended | UV-resistant alternative to ABS |
| PC | 0.5 - 1.0% | Required | High temp, high strength, needs high temps |
| PP | 1.5 - 2.5% | Recommended | Flexible, chemical resistant, hard to adhere |
| TPU | 0.5 - 1.0% | No | Flexible, low shrinkage, slow print speeds |
How to Use This 3D Print Shrinkage Calculator
Dimensional accuracy is one of the biggest challenges in 3D printing. Every thermoplastic material contracts as it cools from its melting point to room temperature, and this 3D print shrinkage calculator gives you the exact scale factor to compensate. Whether you are printing functional parts that need to fit together, molds for casting, or precision prototypes, accounting for shrinkage before you print saves time, filament, and frustration.
Step 1: Select Your Material
Choose the filament material you plan to print with from the dropdown. Each material has a documented shrinkage range based on its thermal properties. ABS and Nylon shrink the most (up to 2-3%), while PLA shrinks very little (0.3-0.5%). The calculator defaults to the mid-range shrinkage value, but you can switch between low, mid, and high using the buttons. If you already know your printer's exact shrinkage rate from calibration prints, select "Custom" and enter your measured value.
Step 2: Enter Your Desired Dimensions
Enter the final dimensions you want after the print cools. You can enter up to three axes (X, Y, Z) to see the compensation for each direction. The calculator applies the formula scale factor = 1 / (1 - shrinkage / 100) to determine how much larger your model needs to be in the slicer. For example, a 50mm part in ABS with 1.5% shrinkage needs to be printed at 50.76mm to end up at 50mm after cooling.
Step 3: Apply the Scale Factor
The results panel shows both the multiplication factor (e.g., 1.0152) and the slicer percentage (e.g., 101.52%). In most slicers, you can apply uniform scaling by entering the percentage. If your material shrinks differently per axis, enter different dimensions and note each scaled value individually. The material comparison table below helps you quickly see how switching materials would change the required scaling.
Step 4: Use the Reverse Calculator for Calibration
The Reverse Calculator tab works backwards from a physical measurement. Print a standard 20mm calibration cube with your material and settings, let it cool completely, then measure each axis with digital calipers. Enter the designed dimension (20mm) and each measured value. The tool calculates your actual shrinkage percentage per axis and provides a recommended scale factor tuned to your specific printer and material combination. This is more accurate than using generic material ranges.
Step 5: Optimize Your Print Settings
Beyond scaling, you can reduce shrinkage at the source. Use an enclosure for ABS, Nylon, and PC to maintain ambient temperature. Increase bed temperature for better adhesion and reduce cooling fan speed for high-shrinkage materials. Higher infill percentages add internal structure that resists contraction. The tips section on this page provides a complete checklist for minimizing shrinkage in your prints.
Frequently Asked Questions
Is this 3D print shrinkage calculator free?
Yes, this shrinkage calculator is completely free to use. There is no signup, no account, and no usage limits. All calculations run locally in your browser, so you can use it as often as you need.
Is my data private when using this tool?
Absolutely. All calculations happen entirely in your browser using JavaScript. No dimensions, material choices, or any other data is sent to a server. Your design measurements stay completely private on your device.
Why do 3D prints shrink after printing?
3D prints shrink because thermoplastic materials contract as they cool from their melting temperature to room temperature. The amount of shrinkage depends on the material's coefficient of thermal expansion, the print temperature, cooling speed, and part geometry. Crystalline materials like Nylon shrink more than amorphous ones like PETG.
How much does ABS shrink in 3D printing?
ABS typically shrinks between 1% and 2% depending on print settings and part geometry. Using an enclosed printer, higher bed temperatures, and slower cooling can reduce ABS shrinkage toward the lower end. For a 100mm part, you would need to scale up to roughly 101-102mm to compensate.
How do I measure actual shrinkage with a calibration cube?
Print a 20mm calibration cube with your chosen material and settings. After it cools completely, measure each axis with digital calipers. Your actual shrinkage percentage is calculated as ((designed - measured) / designed) x 100. Enter these values in the Reverse Calculator tab for precise compensation.
Does PLA shrink when 3D printing?
PLA has the lowest shrinkage of common 3D printing materials, typically only 0.3% to 0.5%. This is one reason PLA is popular for dimensionally accurate parts. However, even this small amount can matter for tight-tolerance assemblies, so compensating for PLA shrinkage is still worthwhile for precision work.
Can different axes shrink by different amounts?
Yes, shrinkage can vary by axis due to layer adhesion direction, infill orientation, and cooling patterns. The Z-axis (layer stacking direction) often shrinks differently than X and Y. This calculator lets you enter separate dimensions for each axis so you can apply the correct compensation per direction.
How can I reduce shrinkage in my 3D prints?
Use an enclosed printer to maintain consistent ambient temperature, increase bed temperature, reduce cooling fan speed, and use a heated chamber if available. Annealing after printing can relieve internal stresses. Slower cooling and higher infill percentages also help reduce warping and uneven shrinkage.