Financial Glossary
Marginal Tax Rate
The marginal tax rate is the tax rate applied to the last dollar of income earned. In a progressive tax system, income is taxed in brackets at increasing rates. Your marginal tax rate is the rate of the highest bracket your income reaches, and it only applies to the portion of income within that bracket, not your entire income.
Example
For 2025-2026, a single filer earning $75,000 falls into the 22% marginal tax bracket. However, only income above $47,150 is taxed at 22%. The first $11,600 is taxed at 10%, and income from $11,601 to $47,150 is taxed at 12%. The overall effective tax rate is lower than 22%.
Frequently Asked Questions
Does my marginal tax rate apply to all my income?
No. In a progressive tax system, only the portion of income within each bracket is taxed at that bracket's rate. Your entire income is not taxed at your marginal rate. This is a common misconception.
How does knowing my marginal tax rate help?
Knowing your marginal rate helps with financial planning decisions, such as whether to work overtime (you know what portion of extra income goes to taxes), contribute to retirement accounts (tax savings at your marginal rate), or realize capital gains.
Related Resources
Official Sources
United Kingdom calculators use data from the following official government agencies:
- HM Revenue & Customs (HMRC) — Income tax bands, National Insurance rates, and pension allowances.
- Office for National Statistics (ONS) — UK earnings data, CPI inflation, and economic statistics.
- MoneyHelper (UK) — Pension guidance, mortgage advice, and financial literacy resources.
Methodology
Our UK calculators use tax bands, National Insurance rates, and contribution limits published by HMRC. Salary and economic data comes from the Office for National Statistics (ONS). Mortgage calculations use average UK interest rates and may vary by lender and individual circumstances. All figures are for educational purposes.
Data Sources
All tax brackets, contribution rates, and economic data used in our calculators are sourced from the official government publications listed above. Rates are updated at least annually to reflect the latest tax year and regulatory changes. Users should verify critical figures with official sources or qualified professionals.
Last updated: June 2026. Information may change; always verify with official sources.
Last Updated: June 2026 — Reviewed Against Official Sources