For the first time in history, mortgage rates have fallen below 4 percent, even as the housing market continues to struggle with bad sales and falling home prices.

Interest rates have already been near historic lows for more than a year, but it's done little to boost home sales.

Mortgage rates are now lower than they were in the early 1950s. The average rate reached 4.08 percent for a few months back then, according to the National Bureau of Economic Research. 

Mortgages back then typically lasted only 20 or 25 years.

The new low rate on a 30-year fixed mortgage is 3.94 percent, with other rates even lower.

"We have a 3.75 percent interest rate on a 30-year fixed FHA loan and 3.875 30-year fix on a conventional mortgage," home realtor Michael Mawood explained. 

"So we've come down a whole percent in the last year, which basically allows someone to buy $10,000 more of house than they could last year for the same monthly payment," he said.

Realtors say buyers still need good credit histories to qualify for a mortgage.