Mass Calculator

Bulk convert (optional): drag & drop a .txt or .csv file, or pick a file .

Format options: value,unit (e.g., 2.5,kg) or single-column values with the Unit selector above used as default. Processed entirely in your browser—nothing is uploaded.

Mass Calculator – Quick Cheat Sheet

Exact definitions (avoirdupois): 1 lb = 0.45359237 kg; 1 oz = 1/16 lb; 1 st = 14 lb.
Metric: 1 t (metric tonne) = 1000 kg; 1 kg = 1000 g = 1,000,000 mg.
Base unit: All conversions pass through kilograms to avoid compounding rounding error.
Precision: Outputs are formatted up to 10 significant digits or 6 decimals (trimmed).
Scope: This tool uses avoirdupois ounces/pounds, not troy ounces (used for precious metals).
Bulk mode: Provide lines like 150,lb or just 150 (defaults to the Unit selector).

Unit symbols used

kg kilogram, g gram, mg milligram, t metric tonne
lb pound (avoirdupois), oz ounce (avoirdupois), st stone

Mass Calculator

Mass Calculator – Quick Cheat Sheet

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