The cost of the conflicts in Iraq and Afghanistan will be £1.4bn this year - more than £3.8m a day - a breakdown of Ministry of Defence figures reveals.
The UK has about 7,000 soldiers in Iraq
The war in Iraq is taking up £2.36m a day, or £860m a year, while that in Afghanistan is costing £1.48m a day, coming to £540m during 2006.
The figures do not include salaries, which would be paid to soldiers anyway.
The Commons defence select committee says it expects the final expense of operations to be higher.
In a report, it also warns about the difficulty in retaining members of the Royal Marines, with the number of regulars leaving "significantly exceeding" target for the past three years.
There are about 7,000 UK troops in Iraq and 6,000 in Afghanistan.
On Wednesday, General Sir Mike Jackson, the former head of the Army, said soldiers' wages were "hardly impressive" and "some accommodation" was "frankly shaming".