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Convert Obolus to Stone (ob to st) instantly with accurate, readable results.
Use our Mass Unit Converter to convert between grams, kilograms, pounds, ounces, and other weight units instantly. Designed for cooking, science, fitness, and engineering needs, this unit conversion tool offers accurate results between metric and imperial systems. Whether you’re tracking body weight, measuring ingredients, or handling heavy machinery, our mass unit conversion calculator has you covered.
Obolus (obol) — a historical unit of mass equal to 10 grains
It is commonly treated as half a scruple, or 10 grains, in historical Roman and apothecaries’ weight contexts; because the obolus was also a coin and ancient weight term, its exact value can vary by period and region. Used mainly in historical medicine, pharmacy, numismatics, and references to ancient or apothecaries’ measures.
- Symbol: obol, obolus
- System: Historical Roman and apothecaries’ unit for mass
- Exact relations: 1 obolus = 1/2 scruple = 10 gr = 647.9891 mg
- Metric equivalents: 1 obolus = 0.6479891 g ≈ 0.000647989 kg
- Typical examples: historical prescriptions may mention oboli; 2 oboli equals scruple; 1 obolus is a little less than 2/3 of a gram.
Stone (st) — an imperial unit of mass equal to 14 pounds
It is defined as exactly 14 avoirdupois pounds; since 1 lb = 0.45359237 kg exactly, 1 st = 6.35029318 kg exactly. Used mainly in the United Kingdom and Ireland for measuring human body weight.
- Symbol: st
- System: Imperial unit for mass
- Exact relations: 1 st = 14 lb = 224 oz = 6.35029318 kg
- Metric equivalents: 1 st ≈ 6.35029 kg ≈ 6350.29 g
- Typical examples: a person weighing 10 st is 140 lb; a small adult ~8 st; a larger adult ~15 st.