The UK has the third largest declared military expenditure in the world, after the United States and China. It is also the second largest spender on military science, engineering and technology. Despite Britain's wide ranging capabilities, recent defence policy has a stated assumption that any large operation would be undertaken as part of a coalition. Bosnia, Kosovo, Afghanistan (Herrick), Iraq (Granby, Desert Fox and Telic) may all be taken as precedent—indeed the last large scale military action in which the British armed forces fought alone was the Falklands War of 1982, in which it was victorious.
The Royal Navy is the second-largest navy of the NATO alliance, in terms of the combined displacement of its fleet, after the United States Navy, with 87 commissioned ships. The Naval Service (which comprises the Royal Navy and Royal Marines) had a strength of 42,700 and is charged with custody of the United Kingdom's strategic nuclear deterrent consisting of four Trident missile submarines, while the Royal Marines provide commando units for amphibious assault and for specialist reinforcement forces in and beyond the NATO area. The British Army had a strength of 150,240 while the Royal Air Force had a strength of 46,800. This puts the total number of active armed forces personnel at around 240,000, nine percent of whom were women.
And this is the numbers you were looking for for the Uk
http://en.wikipedia.org/wiki/British_Armed_Forces#Personnel
Following the 1981-3 reorganisation, the Corps consisted of 1st and 4th Armoured Divisions, which would have manned the front line against the anticipated attack by the Soviet 3rd Shock Army, plus in an in-depth, reserve role the 3rd Armoured Division and finally the 2nd Infantry Division which was tasked with rear-area security.[42]
1st Armoured Division
7th Armoured Brigade
12th Armoured Brigade
22nd Armoured Brigade
3rd Armoured Division (HQ St. Sebastian Barracks, Soest)
4th Armoured Brigade
6th Armoured Brigade
19th Infantry Brigade (in UK)
4th Armoured Division
11th Armoured Brigade
20th Armoured Brigade
33rd Armoured Brigade
2nd Infantry Division
15th Infantry Brigade
24th Infantry Brigade
49th Infantry Brigade
Artillery Division (HQ Ripon Barracks, Bielefeld)
With the end of the Cold War, I (BR) Corps was redesignated in 1992 as a NATO Rapid Reaction Corps under SACEUR and renamed as Headquarters Allied Command Europe Rapid Reaction Corps. HQ ARRC moved to Rheindahlen in 1994.
http://en.wikipedia.org/wiki/British_I_Corps