# Parts per Build Plate Calculator (Additive Manufacturing Nesting)

> Source: https://netray.co/tools/am-parts-per-build-plate-nesting-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Grid nesting estimate for AM build plates with spacing, edge margin and practical nest efficiency, plus packing density and annual machine hours.

## Category

mes-shop-floor

## Industry

Additive Manufacturing

## Audience

- Production planner
- Additive manufacturing lead
- Manufacturing engineer

## Tool

**Kind:** calculator

**Inputs:**

#### Plate X

**Key:** plate_x

**Type:** number

**Default:** 250

**Min:** 10

**Step:** 5

**Unit:** mm

**Help:** Usable build plate length. 250 x 250 is common for metal PBF-LB.

#### Plate Y

**Key:** plate_y

**Type:** number

**Default:** 250

**Min:** 10

**Step:** 5

**Unit:** mm

#### Maximum build height

**Key:** plate_z

**Type:** number

**Default:** 325

**Min:** 10

**Step:** 5

**Unit:** mm

#### Part bounding box X

**Key:** part_x

**Type:** number

**Default:** 40

**Min:** 1

**Step:** 1

**Unit:** mm

**Help:** As oriented for the build, including support footprint.

#### Part bounding box Y

**Key:** part_y

**Type:** number

**Default:** 30

**Min:** 1

**Step:** 1

**Unit:** mm

#### Part bounding box Z

**Key:** part_z

**Type:** number

**Default:** 60

**Min:** 1

**Step:** 1

**Unit:** mm

**Help:** Build height of one part in the chosen orientation.

#### Part solid volume

**Key:** part_vol

**Type:** number

**Default:** 18

**Min:** 0.1

**Step:** 0.5

**Unit:** cm3

#### Part-to-part spacing

**Key:** spacing

**Type:** number

**Default:** 5

**Min:** 0

**Step:** 0.5

**Unit:** mm

**Help:** Gap between bounding boxes for support removal, gas flow and thermal isolation.

#### Edge margin

**Key:** margin

**Type:** number

**Default:** 10

**Min:** 0

**Step:** 1

**Unit:** mm

**Help:** Unused border on each side of the plate.

#### Practical nest efficiency

**Key:** nest_eff

**Type:** slider

**Default:** 80

**Min:** 40

**Max:** 100

**Step:** 1

**Unit:** %

**Help:** Share of the rectangular grid you can actually use after gas-flow shadowing, recoater orientation and inspection access.

#### Layer thickness

**Key:** layer_um

**Type:** select

**Default:** 40

**Options:**

##### 30 um

**Value:** 30

##### 40 um

**Value:** 40

##### 60 um

**Value:** 60

##### 80 um

**Value:** 80

#### Scan volumetric build rate

**Key:** vbr

**Type:** number

**Default:** 18

**Min:** 1

**Step:** 1

**Unit:** cm3/hr

#### Recoat time per layer

**Key:** recoat_s

**Type:** number

**Default:** 9

**Min:** 1

**Step:** 0.5

**Unit:** sec

#### Annual demand

**Key:** demand

**Type:** number

**Default:** 2000

**Min:** 0

**Step:** 50

**Unit:** parts

**Outputs:**

#### Columns along X

**Key:** nx

**Expr:** max(0, floor((plate_x - 2 * margin + spacing) / (part_x + spacing)))

**Format:** integer

#### Rows along Y

**Key:** ny

**Expr:** max(0, floor((plate_y - 2 * margin + spacing) / (part_y + spacing)))

**Format:** integer

#### Grid capacity

**Key:** grid

**Expr:** nx * ny * if(lte(part_z, plate_z), 1, 0)

**Format:** integer

**Description:** Zero when the part is taller than the machine allows.

#### Practical parts per build

**Key:** practical

**Expr:** floor(grid * nest_eff / 100)

**Format:** integer

**Primary:** true

#### Plate footprint utilization

**Key:** footprint_util

**Expr:** practical * part_x * part_y / (plate_x * plate_y) * 100

**Format:** percent

#### Packing density (to part height)

**Key:** pack_density

**Expr:** practical * part_vol * 1000 / (plate_x * plate_y * part_z) * 100

**Format:** percent

**Description:** Solid part volume divided by the plate-area x part-height envelope.

#### Hours per build

**Key:** build_hr

**Expr:** ceil(part_z * 1000 / layer_um) * recoat_s / 3600 + practical * part_vol / vbr

**Format:** hours

#### Machine hours per part

**Key:** hr_per_part

**Expr:** build_hr / max(practical, 1)

**Format:** decimal

#### Builds per year for demand

**Key:** builds_year

**Expr:** ceil(demand / max(practical, 1))

**Format:** integer

#### Machine hours per year

**Key:** machine_hr_year

**Expr:** builds_year * build_hr

**Format:** hours

**Primary:** true

**Chart:**

#### Parts per build vs part spacing

**Type:** line

**X:** spacing

**From:** 2

**To:** 20

**Steps:** 19

**Series:**

- grid
- practical

**Disclaimer:** Rectangular bounding-box grid estimate. Real nests use rotation, interlocking and tilt; confirm in your build preparation software.

## Content

**Intro:** How many parts fit on a plate decides cost per part, delivery and machine hours. This calculator gives a fast bounding-box nesting count, then converts it into build time, packing density and annual builds so you can size capacity before opening the build prep software.

**Sections:**

#### How to use it

**Body:** Enter plate size and maximum height, then the bounding box of one part in the orientation you plan to build, including any support footprint. Set spacing and edge margin from your machine's guidance. The grid count is a simple rectangular array. Because real plates lose positions to gas-flow shadowing, recoater direction and inspection access, apply a practical nest efficiency, typically 70 to 90 percent for bounding-box nests. The chart shows how sensitive the count is to spacing.

**Bullets:**

- Measure the bounding box after choosing orientation, not in the CAD default.
- Include support footprint that extends beyond the part body.
- Lower efficiency for parts that need witness coupons or inspection coupons on the plate.

#### Formulas

**Body:** Columns along X = floor((plate X - 2 x margin + spacing) / (part X + spacing)), and rows along Y likewise. Grid capacity = columns x rows, set to zero if part height exceeds machine height. Practical count = floor(grid x efficiency). Footprint utilization = practical x part X x part Y / plate area. Packing density = practical x part volume / (plate area x part height). Build hours add recoat time (layers x seconds per layer) to scan time (volume / build rate). Annual builds = ceiling of demand / practical count.

#### Reading the output

**Body:** Packing density for solid metal parts is often low, commonly 5 to 20 percent of the envelope, because parts need space for supports and powder removal. Machine hours per part is the figure to compare orientations: a taller orientation may need fewer supports but costs more recoat time per part. Annual machine hours feed capacity planning; divide by realistic available hours, often 5,000 to 6,500 per year per machine after maintenance and changeovers.

#### Common mistakes

**Body:** Treating the grid count as the real count is the biggest error, since sintered or bound parts also need depowdering access. Another is ignoring height: a part that fits in X and Y but is too tall returns zero here for that reason. Tall single orientations also stretch recoat time for every part on the plate. Finally, do not mix parts with very different heights unless you accept that the tallest part sets the layer count for the whole build.

**Cta:** If your planners schedule AM machines in an ERP, we can add nest-aware capacity and build-job planning on top of your work orders.

**Faq:**

#### What spacing should I use?

**Answer:** Follow your machine and process guidance. For metal laser powder bed fusion, several millimeters between bounding boxes is typical, more where supports must be removed by hand. Binder jet and polymer systems allow tighter spacing because there is little thermal interaction.

#### Why is practical count lower than grid count?

**Answer:** Rectangular grids ignore gas-flow direction, recoater clearance, witness coupons and part access. A practical efficiency of 70 to 90 percent models these losses. Replace it with the ratio you actually achieve in build prep.

#### Can I stack parts in Z?

**Answer:** In powder bed processes the build is a single layered volume, so parts are not stacked on top of each other unless they are tall and share supports. In binder jet and polymer systems, true 3D nesting is possible and gives much higher packing density.

#### How do I plan capacity from this?

**Answer:** Multiply builds per year by hours per build, then divide by available machine hours per year. Add changeover, cooldown and maintenance time. If utilization exceeds roughly 80 percent, expect queueing delays.

## Search terms

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