Speaking to the House Armed Services Committee on a defence budget hearing, Mr Rumsfeld said he expects that number to grow to about 325,000.
"There are more that are in training at any given time -- probably 5,000 to 10,000 more," he said.
"Some may have arrived out of training yesterday - they're as green as grass. Some may have arrived out a year, a year and a half ago and they're tested and capable and ready," he told the committee.
US politicians have called for evidence of progress in the preparedness of Iraqi troops to stand on their own, which would eventually allow US forces to withdraw from the country.
Mr Rumsfeld said there is evidence that progress is occurring - although improvement has been more noticeable among Iraq's army than with the police recruits.
Generally, defence forces are better trained than police recruits, Mr Rumsfeld said, "because we have been involved with them".
Joint Chiefs of Staff chairman General Peter Pace has praised the progress of the Iraqi military recruits, saying that a handful of Iraqi battalions just over a year ago has grown into over 130 battalions of 500 to 700 men each.
Ashura preparations
Meanwhile, Iraqi security forced have clamped down around Baghdad and Karbala ahead of the major Shiite religious festival of Ashura, with gunmen wounding six people in the capital.
Police said the gunmen opened fire on a group of Shiites performing religious rituals in the city's Shula district, as hundreds of thousands of people gathered in Karbala a day before the climax of the ritual.
Suicide bombers have attacked the festival in recent years.
Police have closed bridges leading south from the capital, in a bid to block a squad of bombers feared to be heading for Karbala.
The Ashura ceremonies mark the death of the Imam Hussein in the seventh century.