This is a complex area, PCIT have spent hours digesting the latest
Statement of Financial Entitlements (SFE) document and simplified and summarised this in a series of articles with hints and tips.
To calculate the global sum income, your registered population (referred to as Contractor Registered Population or CRP in the SFE) is adjusted by the global sum allocation formula. This includes:
 an adjustment for the age and sex structure of the population
 an adjustment for the additional needs of the population  relating to morbidity and mortality
 an adjustment for list turnover
 a nursing and residential homes index
 an adjustment for the unavoidable costs of delivering services to the population, including a market forces factor and rurality index
We will work through each of these explaining them below.
An adjustment for the age and sex structure of the population:
For the different age and sex bandings a multiplier is applied as follows:

04 
514 
1544 
4564 
6574 
7584 
85+ 
Male 
3.97 
1 
1.02 
2.15 
4.19 
5.81 
6.27 
Female 
3.64 
1.04 
2.19 
3.36 
4.9 
6.56 
6.72

An adjustment for the addiitonal needs of the population  relating to morbidity and mortality
This uses two variables which are: Standardised Limited LongStanding Illness (SLLI) and the Standardised Mortalitty Ratio for those aged under 65 (SMR<65). The calculation for this adjustment is: Practice list * (48.1198 + (0.26115 * SLLI) + (0.23676 * SMR<65)
An adjustment for list turnover
An uplift factor of 1.46 is applied through the formula for all new registrants in their first year of registration.
A nursing and residential homes index
Patients in nursing and residential homes generate more workload than patients with otherewise similar characteristics who are not in homes. A factor of 1.43 is applied in respect of each patient in a nursing or residential home. See our
Registering Care home patients withing EMIS Web article for details of how to ensure this is achieved.
Whilst being in a residential institute attracts a factor of 1.43 to your global sum, there are a series of further normalising calculations that are performed prior to the final allocation of funding. This is complex  see details further on in this article about normalisation calculations that are performed prior to funding allocation.
Adjustments for the unavoidable costs of delivering services to the population, including a market forces factor and rurality index
This adjustment is to reflect differing costs due to geographic location. It is covered by looking at the following areas:
Staff market forces
Informed by the New Earnings Survey and is the same methodology used for general NHS allocations. Weighted by 48% (as this is the average proportion of the global sum accounted for by staff expenses)
Rurality
This looks at population density and dispersion and is governed by the calculation:
Practice list * average distance^0.05 * population density^0
.06 It is only applied to the expenses element of GMS expenditure, and therefore given an overall weighting of 58%
Then the funding is normalised
At each stage of the calculation, the weighted practice populations are normalised (scaled back) to the local area normalised weighted population. This is done so that the impact of each of the adjustments is equal, and ensures that one adjustment does not dominate the others.
Using the age and sex adjustment as an example, the formula for normalising weighted practice populations, for the Global Sum Allocation Formula adjustments is as follows:
age and sex weighted practice population/sum of PCT age and sex weighted practice populations * PCTT normalised weighted population.
The normalised weighted practice populations for each adjustment are then divided by the practice's normalised list size to generate a practice index for each adjustment used in the Global Sum Allocation Formula. The formula for calculating the practice's normalised list size is as follows:
Practice normalised list = Contractor Registered Population * Quarterly PCT Normalising Index
Using the age and sex adjustment as an example, the formula for then calculating the practice index for each adjustment is as follows:
Practice age and sex index = Normalised age and sex weighted practice population/Practice normalised listt size
Combining the adjustments
Each of the six indices are thten applied simultaneously to the practice's normalised list size to calculate the overall weighted practice as follows:
Overall weighted practice population = Practice normalised list size * age and sex index * nursing and residential homes index * additional needs index * MFF index * rurality index.
This overall weighted practice population is then normalised to the national registered population to calculate the Contractor Weighted Population for the Quarter as follows:
Contractors Weighted Population = overall weighted practice population/ sum of PCT overall weighted practice populations * PCT normalised weighted population