Calculator Methodology

Each calculator on Calcsmith has a dedicated methodology page describing its formula, the authoritative HMRC / Revenue Scotland / Welsh Government / FCA / ABI sources used, and the assumptions and limitations of the calculation.

• UK Inheritance Tax Calculator — Methodology
• UK Take-Home Pay Calculator — Methodology
• UK Stamp Duty Calculator — Methodology
• UK Capital Gains Tax Calculator — Methodology
• UK 60% Tax Trap Calculator — Methodology
• UK IR35 Inside vs Outside Calculator — Methodology
• UK Pro-Rata Salary Calculator — Methodology
• UK Mortgage Overpayment Calculator — Methodology
• UK Mortgage Affordability Calculator — Methodology
• UK Buy-to-Let Yield Calculator — Methodology
• UK Pension Tax Relief Calculator — Methodology
• UK Pension Pot Projection Calculator — Methodology
• UK Life Insurance Needs Calculator — Methodology
• UK Critical Illness Cover Calculator — Methodology
• UK Income Protection Calculator — Methodology
• UK Mortgage Life Cover Calculator — Methodology