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Metric conversions

Which old units of measurement are no longer in use for trade?


  • Rood = 1210 square yards


  • Gill = ¼ pint
  • Bushel = 8 gallons
  • Peck = 2 gallons
  • Fluid drachm = 1/8
  • Fluid ounce Minim = 1/60 Fluid drachm

Mass or weight

  • Ton = 2240 pounds
  • Hundredweight = 112 pounds
  • Cental = 100 pounds
  • Quarter = 28 pounds
  • Stone = 14 pounds
  • Dram = 1/16 ounce
  • Grain = 1/7000 pound
  • Pennyweight = 24 grains
  • Ounce apothecaries = 480 grains
  • Drachm = 1/8 ounce


  • Scruple = 1/3 drachm
  • Metric ton = 1000 kg
  • Quintal = 100 kg


  • Rod, pole, perch = 5 ½ yards

How do I find out if my customers weighing instrument can be converted to weigh in metric units?

 Most weighing instruments which weigh pre-packed goods were required to be converted to weigh in metric units (kg or g) in 1995. To complete the metrication process, from 1 January 2000 all sales of loose goods by weight, at retail or wholesale level, are required to be in metric units. To find out if it is possible for your weighing instrument to be converted to weigh in metric units you will need to contact NMO. Before contacting NMO you will need to obtain the following information:- manufacturer's name, model number and type approval certificate number. This information can usually be found on the rating plate attached to the side or rear of the instrument. If the type approval has been granted by NMO then we will probably be able to give you an immediate answer. If the approval had been granted by another Notified Body within the EU then we will probably advise you to either contact the Notified Body direct or to contact the UK Weighing Federation on 01604 622023 for further advice.

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