UK dividends are taxed differently from salary: there is a tax-free dividend allowance, dividends sit on top of your other income, and they use their own rate set. This calculator stacks everything in the right order to give the tax due.
How it works
Dividends are the top slice of income. Using 2024-25 thresholds:
allowance = 500 (taxed at 0%)
basic band up to 37,700 of taxable income → 8.75%
higher band up to 125,140 → 33.75%
additional above 125,140 → 39.35%
Your other taxable income fills the bands first. The taxable dividends (after the 500 GBP allowance) are then placed on top and taxed at whichever band each part falls into. The personal allowance (12,570 GBP) is applied to your total income before the bands.
Example
Other taxable income of 30,000 GBP and dividends of 20,000 GBP. After the 500 GBP allowance, 19,500 GBP of dividends is taxable. The basic rate band (37,700 GBP of taxable income) has 7,700 GBP left after the 30,000 GBP salary, so 7,700 GBP of dividends is taxed at 8.75% and the remaining 11,800 GBP at 33.75%.
Notes
This covers income tax on dividends only. National Insurance does not apply to dividends. The dividend allowance counts toward your band usage even though it is taxed at 0%, which this tool reflects.