Tesla (unit)
SI unit of magnetic flux density, named after Nikola Tesla.
The tesla (symbol: T) is the unit of magnetic flux density (B), also called the magnetic B-field, in the International System of Units (SI). One tesla is equal to one weber per square metre. As with every SI unit named after a person, its symbol is upper case (T) but the name of the unit is written in sentence case (tesla).
- unit_name
- Tesla
- symbol
- T
- quantity
- Magnetic flux density (B)
- system
- International System of Units (SI)
- named_after
- Nikola Tesla
Lore & Background
The tesla is defined via the Lorentz force law: a particle carrying a charge of one coulomb, moving perpendicularly through a magnetic field of one tesla at a speed of one metre per second, experiences a force of one newton. In SI base units, one tesla equals one kilogram per ampere per second squared. The unit can also be expressed in other derived units: one tesla equals one weber per square metre, one newton per ampere-metre, one joule per ampere-square metre, or one volt-second per square metre.
Reader's Guide
The tesla is the standard SI unit for measuring magnetic flux density, replacing the older CGS unit called the gauss. The unit gamma (γ), formerly used in geophysics and defined as 10⁻⁵ gauss, corresponds to 10⁻⁹ tesla; the modern convention is to use the nanotesla (nT) instead. This revision also altered the meaning of conversions between SI units like the tesla and CGS units like the gauss, making them a little uncertain, and use of these conversions has been discouraged in scholarly journals.
Did You Know?
- One tesla equals one weber per square metre.
- The tesla is named after Serbian-American electrical and mechanical engineer Nikola Tesla, upon the proposal of Slovenian electrical engineer France Avčin.
Frequently Asked Questions
Who is Tesla (unit)?
The tesla is the SI unit that measures magnetic flux density, often called the magnetic B-field. It carries the symbol T (capital) while the unit name itself is always written in lowercase.
What are Tesla (unit)'s powers/role?
One tesla corresponds to one weber of magnetic flux spread over one square metre of surface. In practice it tells you how tightly packed the magnetic field lines are at a particular point.
Why is Tesla (unit) important?
It gives the entire scientific and engineering community a single, agreed-upon standard for expressing magnetic field strength. The name also keeps Nikola Tesla, the Serbian-American electrical and mechanical engineer, permanently linked to the measurement of magnetism.
More in Units & Measurement 1-24
Elsewhere in the Units & Measurement universe
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record