Scale could mean:
Weighing scale Weighing scale used for measurement of weight (mass or force)
Scale (map)
Scale (ratio)
Scale factor
Scalability in computing
Scale (zoology)
Zoology: Scale insect, plant parasites which resemble animal scales
Scale parameter, probability and statistics
Logarithmic scale, mathematics
Order of magnitude
Architect's scale — (or draughtsman's scale) is a ruler-like device, which facilitates the production of technical drawings.
Engineer's scale
Zadok scale cereal development
Screen Actors Guild wage standards
Mizan or Balance is a comprehensive treatise on the contents of Islam written by Javed Ahmed Ghamidi, a Pakistani Sunni Islamic scholar.

Astronomy
Palermo Technical Impact Hazard Scale
Torino Scale
Solar flare energy intensity
The constellation Libra (constellation) (Latin for scale) and the zodiac sign Libra (astrology)

Chemistry and physics

Electronegativity
Allred-Rochow scale
Mulliken scale
Pauling scale

Radiodensity
The Hounsfield Scale is a linear transformation of the original linear attenuation coefficient measurement into one in which the radio-density of distilled water at standard pressure and temperature (STP) is defined as zero Hounsfield units (HU), while the radiodensity of air at STP is defined as -1000 HU.

Relative density or specific gravity
The Baumé scale measures specific gravity or relative density.
Brix scale / Degrees Brix (symbol °Bx) is the sugar content of an aqueous solution. One degree Brix is 1 gram of sucrose in 100 grams of solution and represents the strength of the solution as percentage by mass.
Plato scale
Twaddell scale

Temperature

Celsius
Fahrenheit
Réaumur scale

Earth science

 Beaufort scale (wind)
 Fujita scale (tornadoes)
 Mohs scale of mineral hardness
 Saffir-Simpson Hurricane Scale
Okta (cloud cover) - a unit of measurement used to describe the amount of cloud cover at any given location such as a weather station. Sky conditions are estimated in terms of how many eighths of the sky are covered in cloud, ranging from 0 oktas (completely clear sky) through to 8 oktas (completely overcast).

Economics
Scale (economics)
Resource-Based Relative Value Scale, returns to scale

Music
Scale (music)
Bohlen-Pierce scale
Chromatic scale
Deutsch's scale illusion
Diminished scale
Mathematics of musical scales
Major scale
Minor scale
Scale (string instruments)
Scale (album), an album by electronic artist Matthew Herbert

Scale models
Scale model
2 mm scale
HO scale
O scale

Social science
Kinsey scale, sexual orientation
Likert scale, questionnaire format
Phrase completions, questionnaire format

Miscellaneous
The Goldberg scale measures mania and depression.
The Liebowitz social anxiety scale measures the severity of social anxiety disorder.
The Medvedev-Sponheuer-Karnik scale and the Mercalli scale measure the intensity of earthquakes.
The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals.
The Richter scale, a mathematical device to compare the size of earthquakes.
The Scoville Scale measures the hotness of peppers.
The Apgar score is determined by evaluating the newborn baby on five simple criteria on a scale from zero to two, then summing up the five values thus obtained. The resulting Apgar score ranges from zero to 10. The five criteria are summarized using words chosen to form a backronym (Appearance, Pulse, Grimace, Activity, Respiration).