I am going to restrict the analysis to capital ships - battleships (dreadnoughts - super, ordinary, small, semi or pre-versions), battlecruisers and armoured cruisers. If we start counting light cruisers, destroyers and torpedo-boats (let alone subs) my spreadsheet will explode.
Right - Jellicoe's fleet at Jutland (before Beatty lost a chunk of it) comprised: -
Dreadnoughts (BB) = 28
Battlecruisers (BC) = 9
Pre-dreadnoughts (B) covering semi-dreadnoughts and small/slow early dreadnoughts = 0
Armoured Cruisers (AC) = 8 [only counting the latest classes]
Obviously, as war breaks out 3-5 years later, and the fleets clash on day one, actual wartime losses can be added to this total - +1 BB (Audacious) +1 B (King Edward VII) +1 AC (Natal).
In addition there were a number of vessels available but not present at Jutland - newly commissioned & working up, in dockyard hands, in the Med, etc. So we can add: -
+4 BB: Dreadnought; Emperor of India; Queen Elizabeth; Royal Sovereign.
+1 BC: Australia.
+9 B: The seven remaining King Edward VII class + Lord Nelson & Agamemnon.
+6 AC: Devonshire; Carnarvon; Antrim; Roxburgh; Argyll; Cochrane.
Allowing both sides to maximise their pre-war shipbuilding capacity we can add +4 BB for an extra ship in each of the Bellerophon, St. Vincent, Neptune & Queen Elizabeth classes. Also +3 BC for extra Indefatigable, Queen Mary & Tiger single ships.
In the extra two years granted by Dreadnought's late arrival on the scene, the RN can probably add +8 B (Lord Nelson or variants) and +8 AC being the leaked (fake) design for Invincible.
The Japanese do lend their Kongo's to the RN so +4 BC.
Planned vessels should be built in time - the two Revenge-class that were built and the three that were not = +5 BB - but no Renown or Repulse as BC. But we do get the four Admiral-class (Hood and her sisters) +4 BC.
There would be at least two follow-on classes after Revenge (another two year gap in the stretched timeline) so +8 BB - but no Courageous, Glorious or Furious - or at least not in their actual guise.
The Empire supports the Mother Country with additional vessels to follow the examples of Australia, New Zealand & Malaya (hopefully the Australia & New Zealand are Lion-class instead of repeat Indefatigable's). Canada builds the three Queen Elizabeth voted down OTL (+3 BB); they add a battlecruiser (+1 BC) and earlier on some pre-dreadnoughts (repeat King Edward VII) and armoured cruisers (Duke of Edinburgh class) = +4B +4AC. India and South Africa both finance the building of a dreadnought and two armoured cruisers each (+ BB +4 AC).
The naval arms race is not purely euro-centric, with South American navies and Mediterranean governments joining in. Unfortunately Agincourt, Erin and Canada have all been sold by this time (-3 BB) but there will still be plenty on the stocks to "borrow": -
Greece +1 BB +1 BC
Turkey +2 BB
Spain +3 B (the small Espana-class counted as a "small" dreadnought.
Brazil +2 BB +1 BC
Chile +1 BB.
So the Jellicoe / Beatty military-industrial complex known as the Grand Fleet now numbers 58 BB, 24 BC, 25B and 31AC,