ExternalOS
01 / How it works

The four numbers most owners forget.

Salary alone is rarely the true cost. The real cost includes four often-overlooked layers.

When you offer a candidate £30,000, the actual annual cost to your business sits around 12% to 18% higher once Class 1 employer National Insurance, pension auto-enrolment, and holiday accrual are factored in. Get this wrong at hire and the surprise lands at month-end payroll.

This calculator runs the four layers HMRC and The Pensions Regulator actually require, then sense-checks against National Living Wage and National Minimum Wage age bands. April 2026 rates throughout, with the Employment Allowance applied if you're eligible.

02 / The hire

Tell us about the role.

Six fields. Nothing leaves your browser.

The headline figure on the offer letter. Pre-tax. We handle the rest.

Salaried employees get fixed weeks. Hourly / casual workers accrue holiday at 12.07% of hours worked.

Drives the National Minimum Wage / National Living Wage compliance check.

Eligible workers (aged 22 to State Pension age, earning over £10,000) must be auto-enrolled. Employer minimum contribution is 3% of qualifying earnings.

Most small employers can reduce employer NI by up to £10,500/year. Available if total employer NI was under £100k in the previous tax year and you have at least one director or qualifying employee.

03 / The true cost

What the hire actually costs.

Headline cost, breakdown by layer, plus minimum wage compliance.

Annual employer cost
£0

-Above gross salary
-Per month
-Per working day

Compliance checks

Doing this for real? 7 skill files

Beyond the calculator: the full set of UK employer compliance files. Employment law (ERA 2025 ready), employee handbook generator, H&S risk assessment, GDPR compliance, AML/KYC documentation, contracts, and meeting notes. One download per skill, lifetime updates.

£39 vs £200 to £1,500
a UK HR adviser would charge.
One-off payment. Lifetime updates.
UK/EU buyers: Gumroad adds 20% VAT at checkout.
Get the Employer Compliance Pack £39
  • UK Employment Law
  • Employee Handbook
  • H&S Risk Assessment
  • GDPR Compliance
  • AML/KYC Documentation
  • Creative Contracts
  • Meeting Notes & Actions
  • Ready Mixed Concrete cited
  • Autoclenz cited
  • Pimlico Plumbers cited
  • NLW + NMW age bands
  • Holiday Pay 12.07% method
  • Auto-enrol thresholds
  • Right-to-work checks
  • April 2026 rates
  • Lifetime updates

Calculator uses April 2026 UK rates: Employer NI 15% above £5,000 Secondary Threshold, Employment Allowance £10,500, NLW (21+) £12.21, NMW 18-20 £10.00, NMW under 18/apprentice £7.55, qualifying pension earnings £6,240 to £50,270, holiday accrual at 5.6 weeks (12.07% method for irregular hours). Educational tool, not payroll software. For statutory filing, use HMRC Basic PAYE Tools or a payroll provider.