Worked example 1
Worker A earns £20,000/year; Worker B earns £60,000/year. Income tax is 0% on the first £15,000, 20% on £15,001–£40,000, and 40% above £40,000.
(a) Calculate each worker's income tax and average tax rate. (b) Is this system progressive? Explain your answer.
Show solution outline
(a) Worker A (£20,000)
- Taxable income above allowance = £20,000 − £15,000 = £5,000
- Tax paid = 20% × £5,000 = £1,000
- Average tax rate = (£1,000 ÷ £20,000) × 100 = 5%
Worker B (£60,000)
- Tax on income up to £40,000 = 20% × (£40,000 − £15,000) = 20% × £25,000 = £5,000
- Tax on income above £40,000 = 40% × (£60,000 − £40,000) = 40% × £20,000 = £8,000
- Total tax paid = £5,000 + £8,000 = £13,000
- Average tax rate = (£13,000 ÷ £60,000) × 100 = 21.7%
(b) Yes, the system is progressive. This is because the average tax rate increases as income increases. Worker A, the lower earner, pays 5% of their income in tax, while Worker B, the higher earner, pays a much larger proportion at 21.7%.