Interest rate limits for people (not corporations) are generally and histroically limited to about 8-12%.
[citation needed]
The evolution of the relationship between social and legal norms re: what are acceptable interest rates is a very interesting topic, with much cultural diversity and a broad range of case studies from canonical usury regulations in medieval Europe to the prohibition of pay day loans in much of the West in the 20th century, but blanket statements about 'loans being restricted from to 8-12%' lack any basis in reality and economic fundamentals. Just one counter example, I know of many people who took out mortgages (i.e., asset-backed securities!) right here in Belgium (a perfectly normal 'Western' country) less than 30 years ago with interest rates of 15 to 18%, and that was perfectly normal at the time, given inflation rates.
In the U.S. at least, there was a period of 150ish years where that was the case. Most states passed usury laws pretty soon after the U.S. was formed, and by the mid 1800s almost all had pretty strict interest-rate caps. They were loosened a bit towards the end of the 19th century, though some were strengthened again in the early 20th.
In 1978, the Supreme Court ruled that states couldn't enforce their usury laws against nationally chartered out-of-state banks--- the usury laws of the bank's state, not the customer's state, were the only ones that applied. That effectively killed usury laws, because it meant that banks just all incorporated in the states with the weakest usury laws. Then Congress completely preempted state usury laws for nationally-chartered banks in 1980.
But from sometime in the early/mid 1800s to 1978, most states had interest-rate caps in the 8-14% range, and most are still on the books, just ineffectual.
[citation needed]
The evolution of the relationship between social and legal norms re: what are acceptable interest rates is a very interesting topic, with much cultural diversity and a broad range of case studies from canonical usury regulations in medieval Europe to the prohibition of pay day loans in much of the West in the 20th century, but blanket statements about 'loans being restricted from to 8-12%' lack any basis in reality and economic fundamentals. Just one counter example, I know of many people who took out mortgages (i.e., asset-backed securities!) right here in Belgium (a perfectly normal 'Western' country) less than 30 years ago with interest rates of 15 to 18%, and that was perfectly normal at the time, given inflation rates.