BEHIND THE NUMBERS
How this calculation works
Worked example
A £3,000 monthly wage costs £36,000 in a year. Monthly employer NI on £2,583 is £387.45, or £4,649.40 for 12 months. Before pension and other costs, the total is £40,649.40.
Example result: £40,649.40
Use staff groups to avoid repeated entry
A group represents people with the same gross monthly salary and the same number of months in this plan. Split a person into separate rows only when the months do not overlap; the headcount display is then a count of entered group places, not unique people.
Apply employer relief once
Employment Allowance belongs to the eligible employer rather than to each staff member. The calculation pools employer NI before applying the amount you confirm remains available.
Assumptions and rounding
- Each group has constant pay in full monthly pay periods during 2026/27.
- All workers use the standard employer NI treatment without special relief.
- Gross wage-fund mode includes remuneration only. It does not apply UK NI or calculate foreign employer contributions.
Questions about this calculator
Why is employer NI not 15% of the whole wage?
Under the standard monthly treatment, only pay above the £417 monthly secondary threshold is charged at 15% for this period. Special categories can use different thresholds.
Can I claim the full Employment Allowance here?
The tool cannot establish eligibility. If eligible, enter only the unused amount for the employer, up to £10,500 for the tax year.