Free Tax Calculators for the Self-Employed

Estimate your tax savings in seconds

Self-employed people overpay every year — usually by missing deductions or guessing at what they owe. These free calculators estimate your position in seconds, using current HMRC rates, so you know where you stand before you file your Self Assessment.

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Tax Calculators

Mileage Allowance Calculator

Work out your HMRC simplified mileage deduction using the 2026–27 rates (55p / 25p per mile).

Home Office Calculator

Work out your HMRC simplified working-from-home flat-rate deduction by the hours you work at home.

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