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Ore Grade Unit Converter: ppm, g/t, Percent, and oz/ton

Convert assay and geochemical mass-fraction units between parts per billion, parts per million, percent by mass, grams per metric tonne, milligrams per kilogram, kilograms per metric tonne, and troy ounces per U.S. short ton. When every quantity uses the same mass-per-mass sample basis, one ppm equals one milligram per kilogram and one gram per metric tonne. One percent equals 10,000 ppm, 10,000 grams per metric tonne, or 10 kilograms per metric tonne. Precious-metal reporting commonly uses troy ounces per U.S. short ton. This calculator defines one troy ounce as 31.1034768 grams and one short ton as 2,000 avoirdupois pounds or 907.18474 kilograms. Therefore one troy ounce per short ton equals 34.2857143 grams per metric tonne, while one gram per metric tonne equals 0.0291666667 troy ounce per short ton. These definitions matter because an unqualified oz/ton label may be confused with an ordinary avoirdupois ounce, a metric tonne, or a 2,240-pound long ton. Values remain in the browser. Analytics retain only bounded action, input-unit, and output-unit categories—never grade, analyte, element, interval, sample, certificate, project, location, tonnage, recovery, price, value, laboratory, detection limit, qualifier, or notes. The ppm, mg/kg, and g/t equivalence applies to mass per mass on the same basis. It does not automatically apply to milligrams per litre, volume fractions, gases, solution concentrations, wet versus dry basis, feed versus concentrate, recovered product, or another denominator. Preserve the analyte and chemical basis, sample type and interval, original units, wet or dry basis, preparation, digestion, analytical finish, laboratory, certificate, QA/QC, blanks, standards, duplicates, detection and reporting limits, over-range method, significant figures, uncertainty, and every qualifier. Do not turn less-than detection limit, greater-than upper limit, trace, not detected, estimated, or over-range results into false exact numbers. A unit conversion cannot add significant figures, reduce uncertainty, repair sampling bias, validate an assay, establish representativeness, or prove continuity. This tool does not calculate equivalent grade, contained metal, recovered metal, dilution, cutoff grade, net smelter return, payable metal, tonnage, price, value, resources, or reserves. Resource and reserve conclusions require suitable geological evidence, da

Verification resources

Cross-check terminology, classification, methods, and safety with these authoritative external resources.

  • undefined. States that grams per metric ton is equivalent to parts per million by mass and explains assay-ton reporting in troy ounces per short ton.
  • undefined. Publishes conversion factors of 34.285 grams per metric tonne per troy ounce per short ton and 0.02917 in the reverse direction.
  • undefined. Provides SI conversion factors for the troy ounce, metric tonne, and 2,000-pound short ton used to derive the high-precision factor.
  • undefined. Documents the kilogram as the SI unit of mass and the equivalence of 1,000 kilograms to one metric tonne.
  • undefined. Explains that resource and reserve classification depends on geological confidence, data quality, technical and economic information, and modifying factors—not a unit conversion alone.

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Common questions

Is 1 gram per tonne the same as 1 ppm?
Yes, when both describe the same mass fraction on the same sample basis. One metric tonne is one million grams, so one gram per metric tonne is one part per million by mass.
How do I convert percent to ppm?
Multiply percent by 10,000. One percent by mass is 10,000 ppm, 10 kilograms per metric tonne, or 10,000 grams per metric tonne.
How do I convert g/t to troy ounces per short ton?
Multiply grams per metric tonne by 0.0291666667. The reverse conversion multiplies troy ounces per 2,000-pound short ton by 34.2857143.
What does oz/ton mean in this calculator?
It means troy ounces of analyte per U.S. short ton of 2,000 avoirdupois pounds. It does not mean an ordinary avoirdupois ounce, a metric tonne, or a 2,240-pound long ton.
Does converting an assay result prove ore grade, value, or a mineral resource?
No. Conversion changes units only and does not validate sampling, analytical quality, representativeness, continuity, recovery, tonnage, economics, resources, or reserves.

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