All calculations use UK 2026/27 tax year rates and thresholds. These are for illustration only and should not be treated as financial advice.
Income Tax (2026/27)
Personal AllowanceTax-free income
£12,570Basic Rate (20%)£12,571 – £50,270
20%Higher Rate (40%)£50,271 – £125,140
40%Additional Rate (45%)Over £125,140
45%Personal Allowance TaperReduced by £1 for every £2 over £100,000
£100k+National Insurance — Class 1 Employee
Primary ThresholdNo NI below this
£12,570/yrMain Rate£12,570 – £50,270
8%Upper RateOver £50,270
2%Student Loan Repayments
Plan 1 (pre-2012)9% over threshold
£26,900Plan 2 (post-2012)9% over threshold
£29,385Plan 4 (Scotland)9% over threshold
£33,795Plan 5 (post-2023)9% over threshold
£25,000Postgraduate Loan6% over threshold
£21,000Stamp Duty Land Tax (England & NI)
Standard Rates (from April 2025)
| Up to £125,000 | 0% |
| £125,001 – £250,000 | 2% |
| £250,001 – £925,000 | 5% |
| £925,001 – £1,500,000 | 10% |
| Over £1,500,000 | 12% |
First-Time Buyer Relief
Only applies to properties up to £500,000
| Up to £300,000 | 0% |
| £300,001 – £500,000 | 5% |
Additional Property SurchargeSecond homes / buy-to-let
+5%Non-UK Resident SurchargeNot UK resident for 183+ days
+2%Redundancy
Statutory Weekly Pay CapMaximum weekly pay used in calculation
£751Maximum Service YearsCapped for statutory calculation
20 yearsTax-Free LimitFirst £30k is tax & NI free
£30,000
Entitlement by Age
| Under 22 | 0.5 weeks/year |
| 22 – 40 | 1 week/year |
| 41+ | 1.5 weeks/year |
Pension Projection
Tax-Free Lump Sum25% of pot, capped at Lump Sum Allowance
25%Lump Sum Allowance (LSA)Maximum tax-free cash
£268,275Safe Withdrawal RateDefault drawdown assumption
4% / yearGrowth CalculationCompound monthly: pot × (1 + rate/12) + contribution
MonthlyMortgage Calculations
Repayment FormulaStandard annuity formula for fixed monthly payments
AnnuityStress Test RateAffordability check uses current rate + 3%
+3%Max Income MultipleTypical lender cap for affordability
4.5×Overpayment MethodReduces balance, recalculated monthly
Capital reductionBudget & Affordability
Net Income CalculationUses same tax, NI, and student loan logic as salary calculator
ConsistentSalary SacrificeReduces both taxable income and NI-able income
Pre-tax & NIBAYE (Share Incentive Plan)Deducted before tax and NI
Pre-tax & NISAYE (Sharesave)Deducted after tax (from net pay)
Post-taxOther Income (Affordability)Bonuses, rental etc — lenders count 50%
50%General Assumptions
Tax YearAll rates based on
2026/27RegionSDLT applies to England & Northern Ireland only
England & NIData StorageAll data stored in browser localStorage only
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