# Corrugated RSC Blank Size and Web Trim Waste Calculator

> Source: https://netray.co/tools/corrugated-rsc-blank-size-and-web-trim-waste-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Turn inside box dimensions into a regular slotted container blank, see how many fit across your web and what the trim costs you.

## Category

manufacturing

## Industry

Packaging and Printing

## Audience

- Corrugator planner
- Packaging engineer
- Estimator

## Tool

**Kind:** calculator

**Currency:** $

**Inputs:**

#### Inside length

**Key:** len

**Type:** number

**Default:** 400

**Min:** 1

**Step:** 5

**Unit:** mm

**Help:** Inside length of the finished box.

#### Inside width

**Key:** wid

**Type:** number

**Default:** 300

**Min:** 1

**Step:** 5

**Unit:** mm

**Help:** Inside width of the finished box.

#### Inside height

**Key:** hgt

**Type:** number

**Default:** 250

**Min:** 1

**Step:** 5

**Unit:** mm

**Help:** Inside depth between the flap folds.

#### Manufacturer joint (glue flap)

**Key:** flap

**Type:** number

**Default:** 35

**Min:** 0

**Step:** 1

**Unit:** mm

**Help:** Typical glued or stitched joint tab is 30 to 50 mm.

#### Score allowance per fold

**Key:** allow

**Type:** number

**Default:** 3

**Min:** 0

**Step:** 0.5

**Unit:** mm

**Help:** Extra material per score line for the board caliper. Depends on flute and your plant standard.

#### Corrugator web width

**Key:** web_w

**Type:** number

**Default:** 1800

**Min:** 500

**Step:** 10

**Unit:** mm

**Help:** Usable width of the board that comes off the corrugator.

#### Board price

**Key:** price

**Type:** number

**Default:** 0.85

**Min:** 0

**Step:** 0.01

**Unit:** per m2

**Help:** Price or standard cost per square metre of finished board.

**Outputs:**

#### Blank length (cut-off)

**Key:** blank_l

**Expr:** 2 * (len + wid) + flap + 4 * allow

**Format:** decimal

**Description:** Four panels, the joint and four score allowances.

#### Blank width (across web)

**Key:** blank_w

**Expr:** hgt + wid + 2 * allow

**Format:** decimal

**Description:** Height plus two half-width flaps, which meet in the middle.

#### Blanks across the web

**Key:** ups

**Expr:** floor(web_w / blank_w)

**Format:** integer

**Primary:** true

#### Trim width

**Key:** trim

**Expr:** web_w - ups * blank_w

**Format:** decimal

**Description:** Leftover width in mm that becomes scrap.

#### Trim waste

**Key:** trim_pct

**Expr:** trim / web_w * 100

**Format:** percent

**Primary:** true

#### Board per box including trim

**Key:** board_m2

**Expr:** blank_l * web_w / ups / 1000000

**Format:** decimal

**Description:** Square metres charged to each box when trim is absorbed.

#### Board cost per box

**Key:** cost_box

**Expr:** board_m2 * price

**Format:** currency

**Chart:**

#### Trim waste vs web width

**Type:** line

**X:** web_w

**From:** 1000

**To:** 2500

**Steps:** 30

**Series:**

- trim_pct

**Disclaimer:** Blank dimensions follow the common RSC layout. Your plant scoring tools, flute and customer standard may add or subtract a few millimetres. Confirm with a sample cut.

## Content

**Intro:** A regular slotted container blank is four panels, a glue joint and two sets of flaps. This calculator converts inside dimensions into the blank you actually cut, then shows how many fit across your web and how much board you throw away as trim.

**Sections:**

#### How to use it

**Body:** Enter the inside length, width and height of the box, the joint width and a score allowance. Then enter the usable web width of your corrugator and the board price. The result shows blank size, the number of blanks across the web, trim in millimetres and percent, and the cost of board per box once trim is allocated. Use the chart to see how trim changes as the web width moves. A small change in the web you run can swing waste by several percentage points.

#### The formulas behind it

**Body:** For an RSC the blank length is 2 x (L + W) + joint + score allowances, and the blank width is H + W + score allowances, because the two flaps are each half of the box width and meet at the centre. The number across the web is floor(web / blank width). Trim is web minus ups times blank width. Board per box is blank length times web width divided by ups, which charges trim to the box.

**Bullets:**

- Blank length = 2 x (L + W) + joint + 4 x allowance
- Blank width = H + W + 2 x allowance
- Ups = floor(web width / blank width)
- Trim % = (web - ups x blank width) / web

#### Reading the result and common mistakes

**Body:** If trim is above roughly 5 to 8 percent, look at combining orders on the same web, running a different web width, or asking the customer whether the box can move a few millimetres. Mixing up inside and outside dimensions is the most common error, and it produces boxes that are too large by twice the board caliper. Also check which direction the flutes run, since customers often specify it for stacking strength.

**Bullets:**

- Use inside dimensions, not outside
- Check score allowance for your flute type
- Remember slotter trim and side trim on the corrugator
- Sweep the web width before accepting high trim

**Cta:** If you want trim waste and board cost computed automatically from item masters and routings in your ERP, we can build that integration.

**Faq:**

#### Why is the blank width height plus width?

**Answer:** An RSC has two flaps on each end, each roughly half the box width, so they meet in the middle when closed. The blank must cover the height plus both half-width flaps, which adds up to the full width once.

#### What score allowance should I use?

**Answer:** It depends on flute type and your creasing tools. Thin flutes need very little, thick flutes more. Use your plant standard or measure a sample, then enter the per-fold value here.

#### Does this include corrugator side trim?

**Answer:** No. Enter the usable web width after edge trim. If your trim is already removed at the corrugator, use the net width that reaches the converting stage.

#### Can I use it for other box styles?

**Answer:** It is built for RSC. Full overlap, half slotted and die cut styles use different panel layouts, so use the result only as a rough check for those.

## Search terms

rsc box blank size calculator, corrugated blank size formula, corrugated trim waste calculator, regular slotted container dimensions, box blank width and length, corrugated board cost per box, corrugator web width optimization, boxes across the web

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