similarities between us dollar and british pre-decimal currency [solved]

lets say that an american penny (AP) is about equivalent to a british penny (BP)

if you multiply AP by 5 you get a nickel, if you multiply BP by 6 you get a sixpence

double each of those and you get a dime and a shilling respectively

double those and add half of a dime or half of a shilling on to it, you get a quarter in the US and a half crown in the UK

if you double a quarter and a half crown, you get a half dollar and crown respectively

this is where it gets a little weird and far off though

multiply a half dollar by 2 and a crown by 4 to get a dollar or a pound

the last one is a bit of a stretch but as you can see, they are indeed very similar

Ok😉

Imaginative but wrong. By a factor of 2 to 1 at least until the 1920s.

Before 1915, a nickel was worth just over 2d, a dime around 4 - 5d (British 4d groats in Maundy sets, were the same size as dimes, but a bit lighter) A quarter was worth a bit more than a shilling (Around 13 - 13½d = 1/1½). A Half dollar was about 2/2 (Between Florin and Halfcrown) and the Dollar coin was under a crown (4/4 - 4/6). Comparison. American silver dollar weighed 26.2 grams and was 90% silver (About 23.6 grams of it). A 5/- crown weighed 28.28 grams and was 92.5% silver containing 26.16 grams of the silvery goodness - around 12 - 15% more than the American coin.

Before 1915 a British pound was worth $4.25 to $4.50

So a British penny was worth around 2 US cents, a 6d about 12 cents and a shilling around 23 - 24 cents, a Florin was worth around 46 - 48 cents and a gold sovereign was slightly less than a Gold half eagle (weight of 8.3 grams for the half eagle and 7.99 grams for the sovereign).

However bear in mind until 1920 that British coins had more precious metal content than American ones. Silver was 92.5% Fine compared to 90% American silver and gold was 22 carat (91.6667%) compared to 90% for American gold.

When Canada went decimal in 1859, it was around 2 cents canadian to a penny, so a Canadian dollar was worth 50d or 4/2 and thus a British pound was $4.80 Canadian until 1930 or so. A US dollar was always worth more than a Canadian one. This reflected into coins, Canadian quarters and halves were always slightly smaller than US ones. But again the Canadian coins until 1919 were also 92.5% silver, but after 1920 with the collapse of silver coinage in the UK, the Canadians also dropped silver content, but only down to 80%, not 50% and stayed silver through to 1967/68 (It briefly dropped to 50% in 1967 and then was phased out in 1968 except for NCLT after 1971). As for gold Canada only issued 3 gold coins before 1970, the $5 and $10 in 1912 - 14 and $20 commem in 1967. 

After WW1 the value dropped and despite an exchange rate of about $3.50 US for a Sterling pound, the British currency remained at 50% silver whilst American stayed at 90% silver. 7/- of British silver weighed around 19 grams, but dollar equivalent was 22 grams.

In 1946 the British pound became nickel and value was at $3.00, this dropped 30% in 1949 and a British pound was worth barely $2. In 1967 it was devalued further so a pound was only worth $1.40.

To date the Sterling pound has been anywhere between $1.10 and $1.80. Now its around $1.30 I guess as a NZ $ buys 61 US cents and 49 UK Pence.