Find out your Budget 2025 income tax hike cost

The Budget on 26 November looks set to hike income taxes, here’s a calculator to show how much it could affect you.

Rachel Reeves’s Budget on 26 November looks set to increase income tax and other levies – but reporting and rumours of what that could actually entail are very divided.

From National Insurance fiddles to sweeping hikes to the higher and additional rates, millions of taxpayers could be affected in a number of ways.

Dan Neidle, founder of Tax Policy Associates, has created a handy calculator which can show you possible scenarios for income tax hikes and how much it could cost you in extra tax each year.

I proudly present the internet's nerdiest and prettiest tax calculator.

Other calculators just calculate your tax. This one calculates your tax now, and under various Budget proposals. And draws a pretty chart showing the marginal and effective rates for *everyone*. pic.twitter.com/iMMJNTbk7U

— Dan Neidle (@DanNeidle) November 12, 2025

You can select for various outcomes and include aspects such as childcare subsidies in the calculation.

This calculator is the most accurate and comprehensive Mouthy Money has seen. Although we won’t know exactly what the Chancellor will decide to do until she stands at the dispatch box in the House of Commons, this is a good indication of how much her measures could cost you.

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Income tax hike calculator

You can scroll within the tool on the page to see the net costs to your income based on the varying scenarios.

Tax Policy Associates has a more comprehensive breakdown of the scenarios on its site, if you would like to read in further detail.

With thanks to Tax Policy Associates