Mass units spanning laboratory scales, everyday weights, precious metals and large industrial quantities.
All factors come from the central conversion registry.
| Unit | Symbol | System | Definition |
|---|---|---|---|
| Microgram | µg | SI | 1 µg = 10⁻⁹ kg |
| Milligram | mg | SI | 1 mg = 10⁻⁶ kg |
| Unified Atomic Mass Unit | u | SI accepted | 1 u ≈ 1.66053906892×10⁻²⁷ kg |
| Nanogram | ng | SI | 1 ng = 10⁻¹² kg |
| Grain | gr | Avoirdupois/Troy | 1 gr = exactly 64.79891 mg |
| Carat | ct | Metric | 1 ct = exactly 200 mg |
| Gram | g | SI | 1 g = 0.001 kg |
| Pennyweight | dwt | Troy | 1 dwt = exactly 1.55517384 g |
| Avoirdupois Dram | dr | Avoirdupois | 1 dr = exactly 1.7718451953125 g |
| Ounce | oz | Avoirdupois | 1 oz = exactly 28.349523125 g |
| Troy Ounce | oz t | Troy | 1 oz t = exactly 31.1034768 g |
| Pound | lb | Avoirdupois | 1 lb = exactly 0.45359237 kg |
| Kilogram | kg | SI | 1 kg = 1 kg |
| Stone | st | Imperial | 1 st = 6.35029318 kg |
| Slug | slug | US engineering | 1 slug ≈ 14.5939029372 kg |
| Metric Quintal | q | Metric | 1 q = 100 kg |
| US Ton | short ton | US customary | 1 short ton = 907.18474 kg |
| Metric Tonne | t | SI accepted | 1 t = 1000 kg |
| Imperial Ton | long ton | Imperial | 1 long ton = 1016.0469088 kg |
Mass conversions are anchored to the kilogram. The international avoirdupois pound is defined as exactly 0.45359237 kilograms, so common kg↔lb conversions are deterministic rather than estimated.
The interactive calculator, reference table and indexed pair pages all read from the same conversion registry, so unit definitions and formulas stay synchronized.