How much spacing should I leave between parts?

A minimum of 3-5mm between parts is recommended. This prevents parts from fusing if there is any oozing, and gives the cooling fan space to work around each part.

Should I print multiple parts at once?

Batch printing saves time on heating and first layer setup, but increases risk — a failure late in the print wastes more material. For reliable parts, batch printing is very efficient.

What margin should I leave from the bed edge?

Leave at least 5-10mm from the edge. Many printers have clips or less accurate levelling at the edges. The centre of the bed typically gives the best adhesion.

3DPrintCalcs

Build Plate Calculator — Parts per Plate

Work out how many copies of a part fit on your build plate with spacing.

Bed Width (X)

Printable bed width in X. Ender 3 = 235mm; CR-10 Mini = 300mm (Y 220mm); Bambu A1/X1 = 256mm; Prusa MK4 = 250mm.

Bed Depth (Y)

Printable bed depth in Y. Usually the same as the X bed size on square plates (e.g. 235mm or 256mm).

Part Width (X)

Footprint of one part along X — its bounding-box width on the plate, not the model's tallest dimension.

Part Depth (Y)

Footprint of one part along Y — its bounding-box depth on the plate. Rotate parts in your slicer to pack more per plate.

Spacing Between Parts

Gap between adjacent parts; 3-5mm typical for FDM so any ooze does not fuse parts and the cooling fan has room to reach each one (default 5mm).

Edge Margin

Keep-out from the bed edge where clips and less-accurate levelling reduce first-layer adhesion; 5-10mm typical (default 10mm).

How We Calculate This

Formula

Usable area = Bed size - 2 x Edge margin
Parts per row = floor((Usable width + Spacing) / (Part width + Spacing))
Parts per column = floor((Usable depth + Spacing) / (Part depth + Spacing))
Parts that fit = Parts per row x Parts per column (the geometric grid count)
Expected good parts = floor(Parts that fit x (1 - Failure rate)) — a reliability allowance, not a geometry change
Whole-plate utilisation = packed footprint / full bed area x 100 (edge margins are excluded from packing, so this sits below 100%)

The spacing is added to the usable dimension because the last part in each row does not need trailing spacing. "Parts that fit" is the geometric count; the failure rate only adjusts the separate "expected good parts" figure, never the grid itself.

Frequently Asked Questions

Related Calculators

Bed Levelling Calculator

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Brim Width Calculator

Calculate optimal brim width based on part footprint and material shrinkage.

Build Volume Calculator

Calculate usable build volume and check if your model fits the print area.

Adhesion Calculator

Estimate the contact area and adhesion force for your print footprint.

Raft Calculator

Estimate extra material and time for raft adhesion layers.

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Last updated: February 2026

All calculations are estimates. Always verify settings with test prints before committing to final prints.