Reserve Fuel for a 9000km trip
 

Guys, How much trip fuel and reserve fuel should I load for a 9,000 km (4,900 nm) trip. Let's say my aircraft MTOW is around 230,000 kg (507,000 lb) . FL350.

After doing some maths I've estimated:

75,000 kg (165,300 lb) for Trip Fuel

10,800 kg (23,800 lb) for Reserve Fuel (10% time trip + 30 minutes holding at 1500ft at alternative airport)

So Total Fuel Weight = 85,800 kg (189,000 lb)

What do you think guys? Is this an accurate estimation?

I think it might depend on what aeroplane you are "flying".

You seem to be using the wrong basis for your calculation. My airline days ended some years back, but the basis was this (probably still largely valid):

Minimum ramp fuel at departure is:
Allowance for start and taxi (200 kg for B757/767)
Calculated sector burn;
Plus 5% of the above as en-route contingency (can be reduced to 3% if an en-route alternate is specified within a defined geographic zone);
Plus 30 minutes holding at destination;
Plus fuel from go-around at destination to nominated alternate, using realistic route and altitude profile;
Plus final "emergency reserve fuel" (around 400 kg for B757/767 size aircraft).

Yeah as above.

You seem to have missed fuel required to get to alternate.

Also depends on the aircraft but you can use 5 minutes holding fuel instead of 5% trip fuel for contingency which may be less.

The first question is...what is the average fuel burn per hour for your 'aircraft'?