1E3

1e3 is a common shorthand in scientific notation representing 1 × 10^3, which equals 1000. In programming languages, 1e3 is a floating-point literal equal to 1000.0.

The "e" indicates exponent with base 10. It allows compact representation of large and small numbers, e.g., 3.5e4 = 35000, and 6.02e-23 ≈ 6.02 × 10^-23. The syntax is widely supported in languages such as Python, JavaScript, C, Java, and others.

In SI units, 10^3 is the prefix kilo-; 1e3 aligns with the kilo- prefix. However, in computing memory, there is sometimes confusion between decimal prefixes (kilo = 1000) and binary prefixes (kibi = 1024).

Examples of use: 1e3 bytes is 1000 bytes; 1e3 meters is 1000 meters; 1e-3 seconds is 0.001 seconds. In data representation, 1e3 is used for readability of orders of magnitude, particularly in logs, data dumps, and configuration files.

See also: scientific notation; floating-point; SI prefixes.