MEASUREMENT & METHODS

Coulombs (C): electric charge unit guide

Understand coulombs (C) for electric charge. Check base-unit equivalents, examples, comparison tables and source conventions.

What is being measured?

Electric charge is distinct from electric current. Charge transferred depends on current and elapsed time when the corresponding relationship applies.

Ah and mAh measure charge, not energy. Wh conversion requires voltage.

Meaning of C

Coulombs uses the symbol C in this library and measures electric charge. Under the stated reference convention, 1 C = approximately 1 C. This equivalence changes how a known value is written. It does not increase measurement accuracy or establish whether a measurement is appropriate to a real application.

Conversion method

Multiply the value by the source factor (1), then divide by the target factor (1). The factor ratio expresses the same electric charge measurement in the other unit.

Worked example

For a known value of 10 C, the reference conversion gives 10 C. Converting that result back gives approximately 10 C. This reverse check helps catch a reversed factor, but matching round-trip arithmetic alone does not independently verify a source definition.

Common reference values

Input (C)Reference equivalent (C)
11
55
1010
2525
5050
100100

Compare one C with other units

Target unitEquivalent of 1 CDefinition guide
Millicoulombs (mC)1000Read definition
Microcoulombs (µC)1000000Read definition
Nanocoulombs (nC)1000000000Read definition
Ampere hours (Ah)0.000277777777778Read definition
Milliampere hours (mAh)0.277777777778Read definition
Picocoulombs (pC)1000000000000Read definition
Kilocoulombs (kC)0.001Read definition
Femtocoulombs (fC)1000000000000000Read definition

Precision and common mistakes

  • Keep the source and target quantity consistent. A matching symbol is not enough to establish a compatible definition.
  • Record the original measurement precision. Showing twelve significant digits in a table does not make a rounded input more precise.
  • Check symbol capitalization, prefixes and any regional convention in the source. Use the displayed unit definition rather than a similarly named unit.
  • Factors involving repeating fractions or π use finite numerical precision. Round the final answer to the precision justified by your input.

Use a working converter

Source and verification scope

Examples and tables are computed from the versioned unit definitions used by the linked converters. The source access dates appear below. Computandum is independent of the cited organizations; a citation does not mean that a publisher endorses this page or an actual project.

Sources

Read the calculation and sourcing methodology →