UK Income Tax Calculator

Calculate your UK income tax and National Insurance contributions. See your take-home pay based on HMRC tax bands.

Tax Breakdown (2024/25)

Gross Income£45,000
Personal Allowance£12,570
Taxable Income£32,430

Income Tax£6,486
National Insurance£2,594

Total Deductions£9,080
Net Annual Income£35,920
Monthly Take-Home£2,993
Effective Tax Rate20.2%

Income Tax by Band

Basic Rate (20%) on £32,430£6,486

How to Use This Tool

  1. Enter your annual gross income in GBP.
  2. The calculator computes your Personal Allowance, reducing it if your income exceeds £100,000.
  3. Taxable income (income minus Personal Allowance) is split across the Basic, Higher, and Additional Rate bands.
  4. National Insurance (Class 1) is calculated on earnings above the primary threshold.
  5. Review your income tax, National Insurance, total deductions, net income, and monthly take-home pay.

Formula & How It Works

Personal Allowance

Allowance = £12,570 if Income ≤ £100,000, else max(0, £12,570 − (Income − £100,000) / 2)

The tax-free Personal Allowance shrinks by £1 for every £2 earned above £100,000, reaching £0 at £125,140.

Taxable Income

Taxable Income = Gross Income − Personal Allowance

This is the amount subject to Income Tax bands.

Income Tax (2024/25 bands)

20% on the first £37,700 of taxable income + 40% on the next £74,870 (up to £112,570) + 45% on the remainder

Each band rate applies only to the slice of taxable income within it — this mirrors HMRC's Basic (£12,571–£50,270), Higher (£50,271–£125,140), and Additional (over £125,140) rate bands once the Personal Allowance is applied.

National Insurance (Class 1)

NI = (min(Income, £50,270) − £12,570) × 8% + max(0, Income − £50,270) × 2%

NI is charged at 8% on earnings between the £12,570 primary threshold and the £50,270 upper earnings limit, then 2% above that.

Net Income

Net Income = Gross Income − (Income Tax + National Insurance)

This is your annual take-home pay; dividing by 12 gives the monthly figure.

Practical Examples & Common Use Cases

Example: £45,000 salary

Personal Allowance stays at £12,570 (income under £100,000). Taxable income: £32,430, all within the Basic Rate, so Income Tax = £32,430 × 20% = £6,486. National Insurance: (£45,000 − £12,570) × 8% = £2,594. Total deductions ≈ £9,080, leaving net income of about £35,920 (≈£2,993/month).

Example: £120,000 salary (Personal Allowance tapered)

Personal Allowance reduces to £12,570 − (£120,000 − £100,000)/2 = £2,570. Taxable income: £117,430. Income Tax: 20% on £37,700 (£7,540) + 40% on £74,870 (£29,948) + 45% on the remaining £4,860 (£2,187) ≈ £39,675. National Insurance: 8% on £37,700 (£3,016) + 2% on £69,730 (£1,395) ≈ £4,411. Total deductions ≈ £44,086, leaving net income of about £75,914 (≈£6,326/month).

Example: £28,000 salary

Personal Allowance stays at £12,570. Taxable income: £15,430, all within the Basic Rate, so Income Tax = £15,430 × 20% = £3,086. National Insurance: (£28,000 − £12,570) × 8% = £1,234. Total deductions ≈ £4,320, leaving net income of about £23,680 (≈£1,973/month).

Frequently Asked Questions

This calculator uses the 2024/25 UK tax year rates and bands as published by HMRC.

Your Personal Allowance is reduced by £1 for every £2 you earn above £100,000. This means it reaches £0 when your income hits £125,140.

No, this calculator does not include student loan repayments, pension contributions, or other deductions beyond income tax and National Insurance.

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