To convert pennyweights to tons (short), divide by 583333.33. For example, 20 dwt = 20 / 583333.33 = 0.000034 ton. To convert pennyweights to kilograms, divide by 643.0149. For example, 15 dwt = 15 / 643.0149 = 0.0233 kg. To convert pennyweights to grams, divide by 0.643. For example...