Lightest Metals by Density
Key Findings
About This Dataset
Lightest Metals by DensityLithium is the lightest metal at just 0.534 g/cm3, roughly half the density of water, which is why it floats. The three least dense metals, lithium, potassium (0.862) and sodium (0.971), are all alkali metals and all lighter than water itself. There is a clear jump after sodium to a cluster near 1.5 to 1.9 g/cm3 containing rubidium, calcium, magnesium, beryllium and caesium. Magnesium (1.738) and beryllium (1.848) are especially notable because, unlike the soft reactive alkali metals above them, they are structurally useful and widely used in lightweight alloys. Aluminium closes the top ten at 2.70 g/cm3, still light enough to make it the workhorse metal of aviation and packaging.
Data Insights
Numbers, trends & sources behind this chart
Methodology & source
- Data source
- Royal Society of Chemistry
- Coverage
- 10 entities · 10 observations
- Measure
- Density (g/cm3)
- Last updated
- 6 September 2026
- Compiled by
- The ANYSTAT team, from the source above
- Values are shown as reported by the source. Nothing is rescaled, rebased or converted — the only changes are thousand separators and decimals shown to two places.
- Entities are ranked lowest-first, because on this measure a lower number is the better result.
Data Sources & References
All external sources cited in this dataset
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