Tera- Explained

Tera- (; symbol T) is a metric prefix denoting a factor of a short-scale trillion or long-scale billion (10¹² or ).^[1] It was adopted in the International System of Units (SI) in 1960. The prefix is derived from the Greek word Greek, Ancient (to 1453);: τέρας (téras), meaning "monster".^[2]

Exponentiation

• 1 Tm² means one square terametre, or the size of a × square (10²⁴ m²), not square metres (10¹² m²).
• 1 Tm³ means one cubic terametre, or the size of a × × cube (10³⁶ m³), not cubic metres (10¹² m³)

Computing

In computing, tera- may sometimes refer to 2⁴⁰ (1024⁴ or) instead of 10¹², such as in data storage units like the terabyte (TB). The binary prefix tebi- (; symbol Ti) has been adopted by the International Electrotechnical Commission (IEC) to signify 2⁴⁰ and avoid this ambiguity.^[3] JEDEC however still uses tera- for 2⁴⁰ in its memory standards.^[4]

Common usage

Computing

• terabyte (TB): unit of digital storage used in hard disk drives and solid-state drives.
  • terabytes written (TBW), a standard for SSD reliability metrics by JEDEC.
• terabit (Tbit): common in data transmission rates.
• teraFLOPS (TFLOPS): used to describe performance in supercomputers and graphics processing units (GPUs).
  • terascale computing

Electromagnetism

• terahertz (THz): used to describe electromagnetic radiation with frequencies between microwave and infrared ranges, as in:
  • terahertz laser
  • terahertz metamaterial
  • terahertz radiation
    • terahertz spectroscopy
    • terahertz tomography
    • terahertz nondestructive evaluation

Energy and power

• terajoule (TJ): used to express energy yields of large events, such as nuclear explosions or earthquakes.
• terawatt (TW): used in measuring global electrical generation and consumption.
  • Worldwide installed solar capacity reached several terawatts in 2022.^[5]
  • Peak power of a 30-microsecond lightning strike.
• terawatt-hour (TW⋅h or TWh): common unit for large-scale electrical energy production or consumption.

See also

• Binary prefix
• Order of magnitude
• RKM code

External links

• BIPM website

Notes and References

1. Web site: SI Brochure – 9th ed./version 3.02 . Bureau International des Poids et Mesures (BIPM) . 2025-11-06.
2. Web site: tera- . The American Heritage® . 2025-11-06.
3. Web site: Definitions of the SI units: The binary prefixes . 2023-04-05 . physics.nist.gov.
4. Web site: Memory standards . JEDEC . 2025-11-06.
5. Web site: 2024-01-04 . Yearly electricity data . 2024-01-06 . Ember . en-US.