# Weights and Measures

Your guide to how the key metrics and measurements for the art and antiques sector A set of brass and mahogany scales by J. Hare, Birmingham, £35 at Brettels, Newport, September 2011.

### Weight

Silver and other precious metals are traditionally weighed in Troy ounces.

One Troy ounce is equivalent to 31.1g.

The standard or avoirdupois ounce (used for weighing foodstuffs etc.) is equivalent to 28.35g.

Quick Converter: values approximate

 Troy-Metric Metric-Troy 1oz = 31.1g 1g = 0.032oz 2oz = 62.2g 10g = 0.321oz 3oz = 93.3g 50g = 1.6oz 4oz = 124.4g 100g = 3.21oz 5oz = 155.5g 250g = 8oz 6oz = 186.6g 500g= 16oz 7oz = 217.7g 750g = 24.07oz 8oz = 248.8g 1kg = 32.1oz 9oz = 279.9g 10oz = 311g

### Measurements

1in = 2.54cm             1cm = 3/8in (approx)

1ft = 30.48cm            1m = 3ft 3,3/8in

Quick Converter: values approximate

 Imperial-Metric Metric-Imperial 1in = 2.5cm 1cm = 3/8in 2in = 5cm 2.5cm = 1in 3in = 7.5cm 30cm = 12in (1ft) 4in = 10cm 50cm = 20in 5in = 12.5cm 1m = 3ft 4in 6in = 15cm 2m = 6ft 8in 7in = 17.5cm 3m = 10ft 8in = 20cm 9in = 22.5cm 10in = 25cm 11in = 27.5cm 1ft = 30cm 2ft = 60cm 3ft = 90cm 5ft = 1.5m 10ft = 3m

For smaller objects, such as coins and medals, metric measurement in millimetres is the norm. There are 10mm to 1cm, or about 25mm to 1in.

One mile is equivalent to 1.6km, so a 60kmh speed limit is (roughly) 40mph. An engine turned silver 50ft tape measure by James Chesterman and Co, Sheffield 1919, £170 at Woolley & Wallis, Salisbury, January 2011.