What is a weighted list size?

A weighted list size adjusts the raw patient count to reflect the relative healthcare needs of different age and sex groups, used by NHS England to allocate funding more fairly.

Why does my weighted list size differ from my registered list size?

Practices with older or more deprived populations have higher weighted list sizes because these patients require more healthcare resource on average.

Your organisation

Tell us about your PCN or practice. This doesn't affect the calculation — it's used to label your results and export file.

1 Name & region

PCN or practice name

Region Used to note whether a Market Forces Factor may apply to your funding.

2 How would you like to enter your data?

You can enter data for a whole PCN at once, or add each practice separately and see the combined weighted total. Both produce the same result — choose whichever matches the data you have to hand.

Single entry — whole PCN or practice Enter the combined patient numbers for your whole PCN. Quickest if you have totals ready.

Practice by practice Add each practice separately. The tool sums them for your PCN total. Useful if you have per-practice demographic data.

Where do I get age-sex patient numbers from?
The easiest source is NHS Digital — Patients Registered at a GP Practice (published monthly). Find your practice or PCN and download the age-sex breakdown. Your practice system (EMIS, SystmOne) can also produce this report.

Patient numbers by age and sex

Enter the number of registered patients in each group. The weighted total updates automatically as you type.

What are the weights? Each age and sex group uses a different amount of GP services. A patient aged 85+ needs roughly 3–4× more care than an average patient. The weights (shown under each band) reflect this. Your weighted list is your raw list adjusted to reflect how much care your population actually needs — this is what NHS England use to calculate most of your DES payments.

Total registered patients

Raw list size

Weighted list size

Age-sex adjusted

Weighting factor

—

Weighted ÷ raw

Additional weighted patients

—

Above raw count

↓ Enter patient numbers

Age band	Male patients	Female patients	Total	Weighted total
All ages — total	0	0	0	0.0

Additional Needs Index (ANI) — optional

NHS England also applies an Additional Needs Index to account for deprivation in your area. This adjusts your weighted list further — typically between 0.85 (less deprived) and 1.35 (more deprived). Most PCNs don't need to apply this manually as NHS England publish the final adjusted population directly. If you know your ANI, enter it below to see its impact.

Your ANI

Your weighted list size

Based on the patient numbers you entered and NHS England Carr-Hill age-sex weighting factors.

Raw list size

—

Total registered patients

Weighted list size (age-sex)

—

Carr-Hill age-sex adjusted

Enter your patient numbers in Step 2 to see your results here.

£ What this means for your DES funding

Several DES payments are calculated using your adjusted population, not your raw list size. Here is the funding difference your weighting factor makes at 2026/27 rates.

Payment stream	Rate	Based on raw list	Based on weighted list	Difference
ARRS workforce budget	£27.668 /adj. patient	£—	£—	—
Enhanced Access	£8.903 /adj. patient	£—	£—	—
Core PCN — weighted component	£0.748 /adj. patient	£—	£—	—
Total difference (adjusted vs raw)		£—	£—	—

Note: NHS England publishes your official adjusted population in the PCN Adjusted Populations Spreadsheet. This tool estimates your weighted list from your age-sex breakdown — the official figure may differ due to the Additional Needs Index and other adjustments. Always use the official figure for financial planning.

↓ Detailed breakdown

Age band	Weight (M)	Weight (F)	Male patients	Female patients	Raw total	Weighted total	% of weighted list
Total			—	—	—	—	100%

Contribution to weighted list by age band

Age bandShare of weighted listPatientsWeighted

Save your results

Download your weighted list calculation or print it for a board report.

Raw list size

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Weighted list size

—

Weighting factor

—

Organisation

—

↓ Export options

Download for finance reports, board papers, or to feed into the PCN DES Fund Calculator.

— or get a premium report by email —

Important: This calculator uses NHS England Carr-Hill age-sex weighting factors. The resulting weighted list is an estimate for planning purposes. Always use the official adjusted population figure published in the NHS England PCN Adjusted Populations Spreadsheet for DES funding claims and ICB submissions.

About this calculator

NHS England uses a weighted list size rather than a raw patient count to allocate funding to GP practices and Primary Care Networks. Weighting adjusts your registered population to reflect the relative health needs of different age and sex groups — practices with older or more deprived populations receive proportionally higher funding.

This free tool calculates your practice or PCN’s weighted list size using the current NHS England age-sex weighting matrix. Your weighted population is used directly in DES payment calculations, Global Sum payments, and PCN-level funding allocations.

Why weighted list size matters

DES income — PCN DES payments are calculated on weighted list size, not raw registered patients
Global Sum — the core GP contract payment uses weighted population as its primary allocation basis
ICB planning — weighted population figures are used by Integrated Care Boards for resource planning and commissioning decisions
QOF APCA adjustment — the Adjusted Population Prevalence method used in QOF payments also depends on accurate population weighting

Enter your practice or PCN’s patient numbers by age band and sex to calculate your weighted list size instantly. This tool is maintained by orgcentral.app for NHS primary care teams.