Sterling Calculators provides free UK tax and finance calculators and plain-English guides, updated annually for each tax year. Every result is derived from deterministic, band-by-band arithmetic using HMRC's published rates — not black-box estimates.
Most UK tax calculators give you a single number. Sterling Calculators shows the working — every band, every threshold, every deduction — so you can see exactly where your tax comes from and understand what changes when your circumstances change.
The site covers nine calculators and sixty-plus guides across PAYE, self-employment, dividends, corporation tax, capital gains, stamp duty, mortgage overpayments, and VAT. All tools work instantly in your browser with no account or sign-up required.
All calculators are built on a shared JavaScript calculation engine (tax-core.js) using the band structure and thresholds published by HMRC for each tax year. The engine is deterministic — the same inputs always produce the same outputs — and uses integer-penny rounding consistent with HMRC's own methodology.
Income tax thresholds, NI rates, dividend allowances, corporation tax rates, CGT annual exempt amounts, and student loan repayment thresholds are all updated at the start of each tax year. The current version uses 2026/27 rates throughout.
Calculators are designed for the most common UK scenarios using standard assumptions: tax code 1257L (the standard personal allowance code), employment income only (no benefits in kind), England/Wales/Northern Ireland income tax rates (Scotland uses different bands — see note below), and no Marriage Allowance transfer.
Results will differ from your actual tax bill if you have a non-standard tax code, receive benefits in kind, have multiple employments, are Scottish resident, or have circumstances not covered by the inputs provided.
Every guide is written to answer a specific question a real UK taxpayer would ask — "how much is £50,000 after tax?", "should I overpay my mortgage?", "how does the £100k tax trap work?" — and to give a complete, accurate answer with worked examples rather than driving users elsewhere for the actual numbers.
Rates and thresholds are checked against HMRC's published guidance at the start of each tax year. Where HMRC's published figures and legislation differ (which occasionally happens in early April), legislation takes precedence.
Tax rates are updated annually in April when the new tax year begins. If you spot an error — whether a calculation mistake, an outdated rate, or a broken feature — please use the feedback link below. Corrections are usually made within 24–48 hours.
All pages carry a "Last updated" date. The site was last reviewed and updated for the 2026/27 tax year in March 2026.