F is the sixth letter of the Latin alphabet. F may also refer to:

Science and technology

Mathematics

* F or f, the number 15 in hexadecimal and higher positional systems * _''p''''F''_''q'', the hypergeometric function * F-distribution, a continuous probability distribution ** F-test, a statistical test * f, SI prefix femto, factor 10⁻¹⁵ * , Fibonacci number

Computing and engineering

* F (programming language), a subset of Fortran 95 * F Sharp (programming language), a functional and object-oriented language for the .NET platform. *

F* (programming language) F* (pronounced ''F star'') is a functional programming language inspired by ML and aimed at program verification. Its type system includes dependent types, monadic effects, and refinement types. This allows expressing precise specifications ...

, a dependently typed functional language for the .NET platform. * F-measure, the harmonic mean of precision and recall * f, in programming languages often used to represent the

floating point In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can be r ...

* F connector, used for inlet in cable modems * F crimp, a type of solderless electrical connection *

F band (NATO) The NATO F band is the obsolete designation given to the radio frequencies from 3 000 to 4 000 MHz (equivalent to wavelengths between 10 and 7.5 cm) during the cold war period. Since 1992 frequency allocations, allotment and assignments are ...

, a radio frequency band from 3 to 4 GHz * F band (waveguide), a millimetre wave band from 90 to 140 GHz

Physics

* °F, degree on the

Fahrenheit The Fahrenheit scale () is a temperature scale based on one proposed in 1724 by the physicist Daniel Gabriel Fahrenheit (1686–1736). It uses the degree Fahrenheit (symbol: °F) as the unit. Several accounts of how he originally defined his ...

temperature scale * F, for farad, a unit for electric capacitance * or ℱ, the Faraday constant * , focal length of a lens **

f-number In optics, the f-number of an optical system such as a camera lens is the ratio of the system's focal length to the diameter of the entrance pupil ("clear aperture").Smith, Warren ''Modern Optical Engineering'', 4th Ed., 2007 McGraw-Hill Pro ...

(sometimes called f-ratio, f-stop, or written f/), the focal length divided by the aperture diameter *

\vec F

, , , force * , frequency * F (or A), Helmholtz Free Energy * ''F'', the electromagnetic field tensor in electromagnetism *: Often generalized to include the field tensors of other interactions, as in i.e. the gluon field strength tensor. * F region, part of the ionosphere

Chemistry

Fluorine Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactiv ...

, symbol F, a chemical element * f-block, a block of elements in the periodic table of elements * F (or Phe), abbreviation for compound phenylalanine

Biology

* Form (botany) * Form (zoology) *

Bioavailability In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. H ...

, which is expressed as the letter "F" in medical chemistry equations *

Haplogroup F (Y-DNA) Haplogroup F, also known as F-M89 and previously as Haplogroup FT is a very common Y-chromosome haplogroup. The clade and its subclades constitute over 90% of paternal lineages outside of Africa. The vast majority of individual males with F-M89 ...

, a patrilineal haplogroup *

Haplogroup F (mtDNA) Haplogroup F is a human mitochondrial DNA (mtDNA) haplogroup. The clade is most common in East Asia and Southeast Asia.Supannee Kaewsutthi, Nopasak Phasukkijwatana, Yutthana Joyjinda ''et al.'', "Mitochondrial Haplogroup Background May Influence ...

, a matrilineal haplogroup

Music

* F (musical note) * F major, a scale * F minor, a scale * F major chord,

Chord names and symbols (popular music) Musicians use various kinds of chord names and symbols in different contexts to represent musical chords. In most genres of popular music, including jazz, pop, and rock, a chord name and its corresponding symbol typically indicate one or more ...

* f,

Forte (music) In music, the dynamics of a piece is the variation in loudness between notes or phrases. Dynamics are indicated by specific musical notation, often in some detail. However, dynamics markings still require interpretation by the performer dependin ...

* ''F'' (album), an album by Japanese singer Masaharu Fukuyama *''

F Album ''F Album'' is the sixth studio album of the Japanese duo KinKi Kids. It was released on December 26, 2002 and debuted at number two on the Oricon charts, selling 360,102 copies in its first week. The album was certified platinum by the RIAJ ...

'', an album by Japanese duo KinKi Kids *"F", song on the double A-side single " Tsume Tsume Tsume/F" by Japanese metal band Maximum the Hormone

Transport

* F Sixth Avenue Local, a rapid transit service of the New York City Subway * F (S-train), trains on the ring line of Copenhagen's commuter train network * F Market & Wharves, a heritage streetcar line operated by the San Francisco Municipal Railway * The NYSE ticker symbol of the Ford Motor Company *

Ford F-Series The Ford F-Series is a series of light-duty trucks marketed and manufactured by Ford since the 1948 model year. Slotted above the Ford Ranger in the Ford truck model range, the F-Series is marketed as a range of full-sized pickup trucks. ...

, a series of full-size pickup trucks from Ford Motor Company

Military

* F, a class of designation in the United States military aircraft designation systems which stands for "Fighter" * F, a common designation for fighter aircraft * Foxtrot, the military time zone code for UTC+06:00 *

, a radio frequency band from 3 to 4 GHz

Other uses

* ''F'' (film), a 2010 film directed by Johannes Roberts * France, on the

vehicle registration plates of the European Union A vehicle registration plate, also known as a number plate (British English), license plate or licence plate (American English and Canadian English respectively), is a metal or plastic plate or plates attached to a motor vehicle or trailer for off ...

* F (grade), a failing grade * f, the symbol used in the International Phonetic Alphabet for the voiceless labiodental fricative * f, common abbreviation in lexicons meaning ''feminine grammatical gender'' *

Fax Fax (short for facsimile), sometimes called telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer o ...

, referring to a facsimile machine * F, abbreviation for

fax number Fax (short for facsimile), sometimes called telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer o ...

* The citation abbreviation of the '' Federal Reporter'' * F,

Fujitsu is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the l ...

's mobile phones in Japan * Forward position in Australian Rules football * "F" or "F***", sometimes used to censor " fuck". * f, abbreviation for the social networking service Facebook * Common abbreviation for floor (for example, "3F" = 3rd floor) * F word (disambiguation), euphemism for several words beginning with "f" * Dominical letter F for a

common year starting on Tuesday A common year starting on Tuesday is any non-leap year (i.e. a year with 365 days) that begins on Tuesday, 1 January, and ends on Tuesday, 31 December. Its dominical letter hence is F. The most recent year of such kind was 2019 and the next one wi ...

* F, as an online expression of respects to a recently deceased person (as a reference to the videogame '' Call of Duty: Advanced Warfare'') *F, the production code for the 1964 ''Doctor Who'' serial ''

The Aztecs The Aztecs () were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521. The Aztec people included different ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl l ...

'' * ''

"F" Is for Fugitive ''"F" Is for Fugitive'' is the sixth novel in Sue Grafton's "Alphabet" series of mystery novels and features Kinsey Millhone, a private eye based in Santa Teresa, California. Plot summary Henry Pitts is having Kinsey's garage apartment rebuilt af ...

'', the sixth novel in Sue Grafton's "Alphabet mystery" series, published in 1989