Social Security recipients shouldn’t expect a big increase in monthly benefits come January.

Preliminary figures show the annual benefit boost will be between 1 percent and 2 percent, which would be among the lowest since automatic adjustments were adopted in 1975.

Monthly benefits for retired workers now average $1,237, meaning the typical retiree can expect a raise of between $12 and $24 a month.

The size of the increase will be made official Tuesday, when the government releases inflation figures for September. The announcement is unlikely to please a big block of voters — 56 million people get benefits — just three weeks before elections for president and Congress.

The cost-of-living adjustment, or COLA, is tied to a government measure of inflation adopted by Congress in the 1970s. It shows that consumer prices have gone up by less than 2 percent in the past year.