NHS London Weighting (HCAS) Calculator

NHS London Weighting (HCAS) Calculator

If you work for the NHS in or around London on an Agenda for Change (AfC) contract, you are entitled to a High Cost Area Supplement (HCAS), often called "London weighting." It is an extra payment on top of your basic salary that recognises the higher cost of living in the capital. This calculator isolates that single payment — the bit a general NHS pay calculator often blends into one figure — so you can see exactly what your supplement is worth.

HCAS is paid as a percentage of your basic pay, but with a fixed minimum and maximum for each zone. Lower-banded staff are lifted up to the minimum, while higher earners are capped, so the percentage alone rarely tells the full story. Enter your annual basic salary and pick your zone (Inner, Outer or Fringe) to get your supplement, your new gross pay, and an estimated take-home uplift after Income Tax, National Insurance and your NHS pension contribution. It is built for nurses, doctors, healthcare assistants, paramedics, AHPs and admin staff working anywhere from central London out to the fringe counties.

How NHS HCAS / London weighting works

The supplement is calculated in three steps:

1. Raw percentage: your basic salary is multiplied by your zone rate (20%, 15% or 5%).
2. Apply the cap and floor: the result is then clamped to the zone's minimum and maximum payment. If the raw figure is below the minimum, you receive the minimum; if it is above the maximum, you receive the maximum.
3. Add to basic pay: the final HCAS is added to your basic salary to give your new gross pay. HCAS is both taxable and pensionable, so it boosts your pension but is also reduced by tax, NI and pension contributions before it reaches your bank account.

HCAS rates for 2026/27

Zone	Rate	Minimum	Maximum
Inner London	20%	£5,794	£8,746
Outer London	15%	£4,870	£6,137
Fringe	5%	£1,346	£2,270

Worked example

Take a Band 5 nurse on a basic salary of £32,000 working in Inner London:

• Raw 20% of £32,000 = £6,400.
• That sits between the Inner London minimum (£5,794) and maximum (£8,746), so it is not capped. The HCAS is £6,400.
• New gross pay = £32,000 + £6,400 = £38,400.
• The supplement is taxable, NI-able and pensionable. The extra £6,400 attracts 20% Income Tax and 8% National Insurance, and because it lifts pensionable pay from £32,000 to £38,400 it also nudges the worker into the next NHS pension tier (8.3% up to 9.8% on the whole pensionable pay). After all deductions the estimated take-home uplift is around £3,501 per year, or about £292 a month.

By contrast, a healthcare assistant on a £25,000 basic in Inner London would get a raw 20% of just £5,000 — below the £5,794 floor — so their HCAS is lifted up to £5,794.

Frequently asked questions

Is NHS London weighting (HCAS) pensionable and taxable?

Yes. HCAS is treated as part of your pensionable pay, so your NHS pension contributions are calculated on your basic salary plus the supplement. It is also fully taxable and subject to National Insurance, like the rest of your earnings.

What are the Inner, Outer and Fringe zones?

Your zone depends on where your employing trust or site is located. Inner London covers central boroughs (20%), Outer London the surrounding boroughs (15%), and Fringe a ring of nearby counties such as parts of Hertfordshire, Essex, Kent and Surrey (5%). Your contract or payslip states which zone applies.

Why is my HCAS not exactly 20% of my salary?

Each zone has a fixed minimum and maximum cash payment. If the percentage of your salary falls below the minimum you are topped up to it; if it exceeds the maximum you are capped at it. So lower earners often receive more than the headline percentage, and higher earners receive less.

Do all NHS staff in London get HCAS?

HCAS applies to staff on Agenda for Change (AfC) contracts working in a qualifying high cost area. Staff on other contracts (such as some medical and dental terms) may have different arrangements, so check your own terms and conditions.

Source: HCAS rates confirmed against the NHSBSA High Cost Area allowance guidance and NHS Employers Agenda for Change pay scales for 2026/27 — NHSBSA High Cost Area allowance and NHS Employers pay scales. Tax, NI and NHS pension thresholds for 2026/27 from GOV.UK.