Old english units of money

I read in FORSYTE SAGA (http://www.gutenberg.org/files/4397/4397-h/4397-h.htm)

"He was er—an owner of houses, my dear. His hair about your Uncle Swithin's colour; rather a square build. Tall? No—not very tall" (he had been five feet five, with a mottled face); "a fresh-coloured man."

I can calculate the growth of this man 5*ft+5*in=165 cm

But I cannot calculate this:

"Old Jolyon stepped out, and, in paying the cab fare, for the first time in his life gave the driver a sovereign in mistake for a shilling."

Can anybody send me a Mathcad-sheet with

shilling:=?

sovereign:=shilling

etc