National Insurance Calculator
Estimate annualised employee Category A Class 1 or self-employed Class 4 contributions, with separate main-rate and upper-rate amounts.
Rule year: 2026/27 · GBP · Sources checked
Estimated annual National Insurance
Ordinary Category A employees below State Pension age or supported self-employed Class 4 profits. No other NI categories, exemptions, deferment, mixed employment or voluntary Class 2. Annual thresholds are used; pay-period calculations and rounding can differ.
For informational purposes only. This estimate is not financial advice, a tax return, a payroll calculation or a lender decision. See the supported circumstances and exclusions below.
How this calculator works
The selected model applies different main rates to earnings between the supported lower and upper annual thresholds. Amounts above the upper threshold use the upper rate. Ordinary employee NI is usually calculated by pay period; this annual-threshold model provides a planning approximation, not a reconstruction of payroll. Class 4 is based on the entered self-employed profit and does not include voluntary Class 2 payments.
Formula and rules
Main contribution = max(0, min(earnings, 50,270) − 12,570) × selected main rate. Upper contribution = max(0, earnings − 50,270) × 2%. Main rate: employee 8%, Class 4 6%.
Assumptions and limitations
Ordinary Category A employees below State Pension age or supported self-employed Class 4 profits. No other NI categories, exemptions, deferment, mixed employment or voluntary Class 2. Annual thresholds are used; pay-period calculations and rounding can differ.
Worked example
At £50,000 employee earnings, the annual model charges 8% on £37,430 above £12,570, giving £2,994.40. The same profit entered under Class 4 uses 6% and gives £2,245.80.
- Estimated annual National Insurance
- £2,994.40
- Main-rate contribution
- £2,994.40
- Upper-rate contribution
- £0.00
- Monthly average
- £249.53
Official sources and review
Reviewed against the sources below on 2026-10-06. Rates are held in versioned rule modules. Versioned rules, official source review and year-specific calculation tests.
- HMRC: Rates and thresholds 2026 to 2027 ↗
Regional PAYE bands, Category A NI, student-loan plans and current minimum wage.
- GOV.UK: National Insurance rates ↗
Category A employee rates and Class 4 self-employed rates; no compulsory Class 2 charge in this model.
Common questions
Why does this differ slightly from monthly payslips?
Non-director employee NI is generally calculated for each pay period using period thresholds and rounding. This tool uses annual thresholds for its labelled estimate.
Is employer NI deducted from this result?
No. The employee model shows primary contributions only. Employer contributions are a separate cost.
Does the self-employed option include voluntary Class 2?
No. It models Class 4 only. Voluntary Class 2 and eligibility for credited contributions need separate consideration.