---
title: "Corrugated cardboard — density, melting point and properties"
description: "Corrugated cardboard has a density of 160 kg/m³ (100–250). Melting point, strength, conductivity, what it is used for, and whether it floats, rusts or is magnetic."
url: https://atoneplace.net/material/cardboard/
site: "At One Place"
---

# Corrugated cardboard

**Density of corrugated cardboard: 160 kg/m³ (100–250)**

0.16 g/cm³ · 10.0 lb/ft³

The board is mostly air: two flat liners with a fluted layer between, giving an overall density around 160 kg/m³ even though the paper it is made from is 600-800. The flute is a row of arches, and it carries load edge-on — a stack of boxes is held up by the corrugations acting as tiny columns, which is why a box crushes instantly if laid on its side. Damp destroys it completely, since the strength lives in hydrogen bonds between fibres that water simply undoes.

## Properties

- **Density:** 160 kg/m³ (100–250) — 0.16 g/cm³
- **Floats in water:** Yes
- **Magnetic:** No

## What it is used for

- Shipping boxes and transit packaging
- Pallet layer pads and dividers
- Display stands and temporary furniture
- Insulation and mulch in gardening

## How it compares

*Water is 1,000 kg/m³. Anything with a shorter bar than water floats in it.*

- air: 1.2 kg/m³
- expanded polystyrene foam: 20 kg/m³
- rigid polyurethane foam: 40 kg/m³
- corrugated cardboard: 160 kg/m³
- Water — the float line: 1,000 kg/m³
- tungsten: 19,250 kg/m³
- gold: 19,300 kg/m³
- platinum: 21,450 kg/m³

*Water is 1,000 kg/m³. Anything below that floats.*

| Material | Density | Relative to water |
| --- | --- | --- |
| rigid polyurethane foam | 40 kg/m³ | 0.04× |
| expanded polystyrene foam | 20 kg/m³ | 0.02× |
| air | 1.2 kg/m³ | 0.00× |
| corrugated cardboard ← | 160 kg/m³ | 0.16× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |

## Does it rust?

Corrugated cardboard contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.

## Is it magnetic?

Corrugated cardboard is not a metal and has no ferromagnetic response.

## Common questions

### What is the density of corrugated cardboard?

160 kg/m³ (100–250), or 0.16 g/cm³.

### Does corrugated cardboard float?

Yes. At 160 kg/m³ it is less dense than water's 1,000.

### Is corrugated cardboard magnetic?

Corrugated cardboard is not a metal and has no ferromagnetic response.

## Related pages

- [Does corrugated cardboard float?](https://atoneplace.net/does-it-float/cardboard/)
- [Air](https://atoneplace.net/material/air/)
- [Ice](https://atoneplace.net/material/ice/)
- [Paper](https://atoneplace.net/material/paper/)
- [Cork](https://atoneplace.net/material/cork/)
- [Leather](https://atoneplace.net/material/leather/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)