MEASUREMENT & METHODS

stones (st): mass unit guide

Understand stones (st) for mass. Check base-unit equivalents, examples, comparison tables and source conventions.

What is being measured?

Mass is distinct from force or weight. Pounds of mass and pounds-force belong to different quantities.

Pounds and ounces use international avoirdupois mass. US tons are short tons; a metric carat is 200 mg.

Meaning of st

stones uses the symbol st in this library and measures mass. Under the stated reference convention, 1 st = approximately 6.35029318 kg. 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 (6.35029318), then divide by the target factor (1). The factor ratio expresses the same mass measurement in the other unit.

Worked example

For a known value of 10 st, the reference conversion gives 63.5029318 kg. Converting that result back gives approximately 10 st. 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 (st)Reference equivalent (kg)
16.35029318
531.7514659
1063.5029318
25158.7573295
50317.514659
100635.029318

Compare one st with other units

Target unitEquivalent of 1 stDefinition guide
Kilograms (kg)6.35029318Read definition
Grams (g)6350.29318Read definition
Pounds (lb)14Read definition
Ounces (oz)224Read definition
milligrams (mg)6350293.18Read definition
metric tons (t)0.00635029318Read definition
US short tons (US ton)0.007Read definition
carats (ct)31751.4659Read 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 →