Routing number of commercial bank of Ethiopia? A pound is equal to 20 shillings, a guinea is equal to 21-or at least they used to be, since guineas and shillings, strictly speaking, aren't around anymore. 25 guineas would then be the equivalent of 25 pounds and 25 shillings, or 26 pounds 5 shillings. including the effects of capital investment, technology innovation, education, and health, anomalies. How much was a guinea worth in the 18th century?