# Calcsmith — UK Personal Finance Calculator Hub > Calcsmith publishes free, accurate UK personal finance calculators with verified rate data sourced from HMRC, Revenue Scotland, and Welsh Government. All calculators use audit-verified 2026/27 rates and are mathematically tested. We are not FCA-regulated and do not provide personal financial advice — calculator outputs are estimates for educational purposes. ## About We focus on transparent, mathematically correct UK tax and protection calculators. Every rate constant is verified against authoritative sources and dated; every calculator shows its working. Source data: https://calcsmith.co.uk/data/ ## Calculators ### Tax - [Capital Gains Tax Calculator](https://calcsmith.co.uk/uk/tax/capital-gains-tax-calculator/): UK CGT for shares and residential property, post-October 2024 unified rates. - [Inheritance Tax Calculator](https://calcsmith.co.uk/uk/tax/inheritance-tax-calculator/): NRB, RNRB, taper, spouse transfer, and 36% reduced rate for charitable estates. - [60% Tax Trap Calculator](https://calcsmith.co.uk/uk/tax/60-percent-tax-trap-calculator/): Models the personal allowance taper between £100,000 and £125,140. ### Salary - [Take-home Pay Calculator](https://calcsmith.co.uk/uk/salary/take-home-pay-calculator/): UK and Scottish PAYE with tax codes, student loans, and pension. - [IR35 Inside vs Outside Calculator](https://calcsmith.co.uk/uk/salary/ir35-inside-vs-outside-calculator/): Compare contractor take-home under IR35 inside vs outside structures. - [Pro-Rata Salary Calculator](https://calcsmith.co.uk/uk/salary/pro-rata-salary-calculator/): Convert annual salary to part-time, hourly, or pro-rated equivalents. ### Property - [Stamp Duty Calculator](https://calcsmith.co.uk/uk/property/stamp-duty-calculator/): SDLT (England), LBTT (Scotland), LTT (Wales) with first-time buyer relief and second-home surcharges. - [Mortgage Overpayment Calculator](https://calcsmith.co.uk/uk/property/mortgage-overpayment-calculator/): Models interest savings and term reduction from extra payments. - [Mortgage Affordability Calculator](https://calcsmith.co.uk/uk/property/mortgage-affordability-calculator/): Income multiple and disposable-income affordability with stress testing. - [Buy-to-Let Yield Calculator](https://calcsmith.co.uk/uk/property/buy-to-let-yield-calculator/): Gross and net yield with Section 24 modelling for higher-rate landlords. ### Pension - [Pension Tax Relief Calculator](https://calcsmith.co.uk/uk/pension/pension-tax-relief-calculator/): Salary sacrifice, relief at source, and net pay arrangements with higher-rate relief. - [Pension Pot Projection Calculator](https://calcsmith.co.uk/uk/pension/pension-pot-projection-calculator/): Compounded growth with pessimistic/expected/optimistic scenarios. ### Insurance - [Life Insurance Needs Calculator](https://calcsmith.co.uk/uk/insurance/life-insurance-needs-calculator/): Needs analysis from debts, income replacement, childcare, and dependants. - [Critical Illness Cover Calculator](https://calcsmith.co.uk/uk/insurance/critical-illness-calculator/): Cover sizing for income replacement and treatment costs during recovery. - [Income Protection Calculator](https://calcsmith.co.uk/uk/insurance/income-protection-calculator/): Monthly benefit needs analysis with SSP, employer sick pay, and industry caps. - [Mortgage Life Cover Calculator](https://calcsmith.co.uk/uk/insurance/mortgage-life-cover-calculator/): Decreasing term, level term, and joint life first death cover for mortgage protection. ## Methodology - [Methodology Index](https://calcsmith.co.uk/uk/methodology/): All Calcsmith calculator methodologies in one place. - [Inheritance Tax Methodology](https://calcsmith.co.uk/uk/methodology/inheritance-tax-calculator/): Formula, sources, and assumptions for the UK Inheritance Tax Calculator. - [Take-Home Pay Methodology](https://calcsmith.co.uk/uk/methodology/take-home-pay-calculator/): PAYE income tax, NI, student loan, and pension calculation methodology. - [Stamp Duty Methodology](https://calcsmith.co.uk/uk/methodology/stamp-duty-calculator/): SDLT/LBTT/LTT band-by-band calculation with first-time buyer relief and surcharges. - [Capital Gains Tax Methodology](https://calcsmith.co.uk/uk/methodology/capital-gains-tax-calculator/): Post-October-2024 unified CGT rates with basic-rate headroom logic. - [60% Tax Trap Methodology](https://calcsmith.co.uk/uk/methodology/60-percent-tax-trap-calculator/): Personal allowance taper between £100,000 and £125,140. - [IR35 Methodology](https://calcsmith.co.uk/uk/methodology/ir35-inside-vs-outside-calculator/): Inside vs outside IR35 take-home comparison with corporation tax and dividends. - [Pro-Rata Salary Methodology](https://calcsmith.co.uk/uk/methodology/pro-rata-salary-calculator/): FTE-to-part-time salary conversion logic. - [Mortgage Overpayment Methodology](https://calcsmith.co.uk/uk/methodology/mortgage-overpayment-calculator/): Standard amortisation with monthly compounding and overpayment iteration. - [Mortgage Affordability Methodology](https://calcsmith.co.uk/uk/methodology/mortgage-affordability-calculator/): Income-multiple and stressed-affordability dual-cap formula per FCA MCOB 11. - [Buy-to-Let Yield Methodology](https://calcsmith.co.uk/uk/methodology/buy-to-let-yield-calculator/): Gross / net yield with Section 24 finance-cost tax credit modelling. - [Pension Tax Relief Methodology](https://calcsmith.co.uk/uk/methodology/pension-tax-relief-calculator/): RAS, net pay, and salary sacrifice relief formulas with annual allowance taper. - [Pension Pot Projection Methodology](https://calcsmith.co.uk/uk/methodology/pension-pot-projection-calculator/): Real-terms compound growth with FCA COBS 13 Annex 2 scenario rates. - [Life Insurance Needs Methodology](https://calcsmith.co.uk/uk/methodology/life-insurance-needs-calculator/): Needs-analysis sizing from debts, income replacement, and dependants. - [Critical Illness Methodology](https://calcsmith.co.uk/uk/methodology/critical-illness-calculator/): Recovery-period income replacement and treatment-cost sizing per ABI standards. - [Income Protection Methodology](https://calcsmith.co.uk/uk/methodology/income-protection-calculator/): Monthly benefit sizing with SSP, employer sick pay, and industry caps. - [Mortgage Life Cover Methodology](https://calcsmith.co.uk/uk/methodology/mortgage-life-cover-calculator/): Decreasing term, level term, and joint-life-first-death structure selection. ## Source Data - [Per-calculator methodology pages](https://calcsmith.co.uk/uk/methodology/): How each calculator works, what assumptions it makes, and what authoritative source each rate comes from. - [Rate data CSV exports](https://calcsmith.co.uk/data/): Granular UK tax and protection rate data as machine-readable CSVs, by tax year.