perday

Perday is a rarely used one-word form of the phrase "per day." In standard English, the expression meaning "for each day" is normally written as two words ("per day") or hyphenated as a compound adjective ("per-day") when used before a noun (for example, "per-day rate").

In data reporting and analysis, "per day" expresses daily rates, such as calories per day, revenue per day, or traffic per day. It is also common in medical contexts to indicate daily intake amounts (for example, "dosage: 50 mg per day"). In operations and logistics, daily measurements track production, energy use, or workload across separate days.

Because "perday" as a single word is nonstandard, its appearance may indicate a typographical error, a stylized brand name, or a field label in software or datasets. When writing formally, using "per day" or "per-day" improves readability and avoids ambiguity.

In practice, most style guides and editors prefer the two-word form for ordinary usage and reserve the hyphenated "per-day" when functioning as an adjective before a noun. The concept itself is simple: it denotes a rate or quantity measured for each day in a given period, and it is widely applied across fields such as nutrition, finance, healthcare, and operations.