---
title: "Mercury — density, melting point and properties"
description: "Mercury has a density of 13,534 kg/m³. Melting point, strength, conductivity, what it is used for, and whether it floats, rusts or is magnetic."
url: https://atoneplace.net/material/mercury/
site: "At One Place"
---

# Mercury

**Density of mercury: 13,534 kg/m³**

13.53 g/cm³ · 844.9 lb/ft³

The only metal that is liquid at room temperature, and at 13,534 kg/m³ dense enough that steel and lead ballast float on it. That density is why a barometer using mercury is 760 mm tall while a water one would need to be over 10 metres. It has no useful tensile strength or modulus because it is a liquid, and its vapour is cumulatively neurotoxic, which is why it has been designed out of thermometers and switches almost everywhere.

## Properties

- **Density:** 13,534 kg/m³ — 13.53 g/cm³
- **Melting point:** -38.8 °C
- **Thermal conductivity:** 8.3 W/(m·K)
- **Floats in water:** No
- **Magnetic:** No

## What it is used for

- Barometers and manometers
- Fluorescent and discharge lamps
- Tilt switches and thermostats (largely phased out)
- Laboratory reference standards

## 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
- Water — the float line: 1,000 kg/m³
- mercury: 13,534 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× |
| mercury ← | 13,534 kg/m³ | 13.53× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |

## Does it rust?

Mercury does not rust — rust is iron oxide specifically — but it does corrode, forming its own oxide or salts over time.

## Is it magnetic?

Mercury is not ferromagnetic. It is often assumed to be because it is a metal, but most metals are not — only iron, nickel, cobalt and a few alloys are attracted to an ordinary magnet.

## Common questions

### What is the density of mercury?

13,534 kg/m³, or 13.53 g/cm³.

### Does mercury float?

No. At 13,534 kg/m³ it is denser than water.

### Is mercury magnetic?

Mercury is not ferromagnetic. It is often assumed to be because it is a metal, but most metals are not — only iron, nickel, cobalt and a few alloys are attracted to an ordinary magnet.

## Related pages

- [Does mercury float?](https://atoneplace.net/does-it-float/mercury/)
- [Aluminum](https://atoneplace.net/material/aluminum/)
- [Copper](https://atoneplace.net/material/copper/)
- [Gold](https://atoneplace.net/material/gold/)
- [Titanium](https://atoneplace.net/material/titanium/)
- [Iron](https://atoneplace.net/material/iron/)
- [Lead](https://atoneplace.net/material/lead/)
- [Tungsten](https://atoneplace.net/material/tungsten/)
- [Silver](https://atoneplace.net/material/silver/)

## Sources

- Wikidata — Wikimedia Foundation (https://www.wikidata.org/) [CC0 1.0]