Professional reference · private review version
Residue concentration converter
Exact mass-fraction equivalents for mg/kg, µg/kg, ppm and ppb. No density assumptions, legal limit lookups or liquid concentration conversions.
Mass / mass concentration
Finite, nonnegative. Small decimal and scientific notation supported, for example 1e-9.
Equivalent concentrations
- mg/kg
- 1
- µg/kg
- 1000
- ppm (mass fraction)
- 1
- ppb (mass fraction)
- 1000
Display: up to 12 significant digits. Copy retains full calculated precision.
Scope & interpretation
1 mg/kg = 1 ppm (mass fraction) = 1,000 µg/kg = 1,000 ppb (mass fraction). A µg/kg is a microgram per kilogram; ppm and ppb here mean parts per million and billion by mass, not by volume or amount of substance.
These are exact unit scaling factors, not improved analytical precision. This tool does not convert mg/L, apply density or dilution factors, handle formulation percentages, or retrieve MRLs. Keep the same sample basis, matrix and residue definition when comparing results.
Unit equivalence does not establish compliance, health risk or product safety.
Calculations remain in this browser. Inputs and results are not saved or transmitted. Specialist review and separate owner approval are required before public release.
Official residue programme context
Explore historical sampling evidence, not a limit lookup or a matched laboratory record.