Three common ways to express a premium
Employers can describe enhanced pay in different ways. The calculation must match the wording that actually applies to your shifts.
| Method | Example | Extra premium on £16/hour |
|---|---|---|
| Percentage | 20% premium | £3.20 extra/hour |
| Fixed amount | £2.50/hour allowance | £2.50 extra/hour |
| Multiplier | 1.25× | £4.00 extra/hour |
Percentage premium/hour = base rate × premium percentageMultiplier premium/hour = base rate × (multiplier − 1)Worked annual example
A worker earns £16/hour and receives a 20% night premium for 8 eligible hours on three shifts per week. The extra premium is £3.20/hour, or £25.60 per eligible shift. At three eligible shifts for 46 working weeks, the illustrative annual premium is £3,532.80 gross.
Do not assume every shift qualifies
The premium-eligible hours may be narrower than the shift itself. A policy might enhance only certain night hours, weekends or specific duties. Use the qualifying hours and frequency from the employer's terms rather than the total roster length.
The result is gross extra pay. It does not calculate tax, National Insurance, pension deductions or legal entitlement.
Test the frequency as well as the rate
The annual value is often more sensitive to how many eligible shifts you actually work than to a small change in the premium rate. Using the £25.60 premium-per-shift example above for 46 working weeks gives the following illustration.
| Eligible shifts/week | Premium/shift | Illustrative annual premium |
|---|---|---|
| 1 | £25.60 | £1,177.60 |
| 2 | £25.60 | £2,355.20 |
| 3 | £25.60 | £3,532.80 |
| 4 | £25.60 | £4,710.40 |
That is why the calculator asks for eligible shifts and working weeks separately. If your rota alternates between premium and non-premium duties, use an average frequency that reflects the actual cycle rather than the maximum number of nights you could work in one week.
Check the qualifying rule before comparing jobs
Two employers can both advertise a “20% night premium” while applying it to different hours. One might enhance an entire night shift; another might apply the percentage only between defined clock times. Confirm the eligible hours, whether paid breaks count, and whether the premium is pensionable before treating the annualised number as directly comparable.