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Free Financial Calculators
Professional-grade tools for compound interest, tax, mortgages, investments, and more.
Most Popular
Compound Interest Calculator
See how your money grows over time with the power of compounding.
- Multiple compounding frequencies
- Monthly contributions
- Year-by-year breakdown chart
Most Popular
Percentage Calculator
Calculate percentages, percentage change, and percentage of a number.
- Three calculation modes
- Instant results
- Step-by-step formula
Most Popular
Income Tax Calculator
Calculate UK or US income tax, payroll taxes, and take-home pay.
- UK & US Federal supported
- NI / FICA breakdown
- Student loan & 401(k)
New
Pension Contribution Optimiser
Work out how much to pay into your pension this year — and what it is worth.
- Tax relief & salary sacrifice
- Annual allowance & carry-forward
- Trade-off in today's money
Currency Converter
Convert between major world currencies with live ECB rates.
- 30+ currencies
- ECB exchange rates
- Instant conversion
Take Home Pay Calculator
See exactly how much you take home after tax, NI, and deductions.
- Full deductions waterfall
- Monthly & weekly breakdown
- Pension / 401(k) contributions
VAT Calculator
Add or remove VAT at standard, reduced, or custom rates.
- Add or remove VAT
- Standard, reduced & custom rates
- Quick reference table
Mortgage Calculator
Calculate monthly mortgage payments and see your amortisation schedule.
- Repayment & interest-only
- Amortisation schedule
- Total interest breakdown
Inflation Calculator
See how inflation erodes purchasing power over time.
- Custom inflation rate
- Dual-line chart
- Purchasing power erosion
Percentage Change Calculator
Calculate the percentage increase or decrease between two values.
- Colour-coded results
- Absolute & multiplier
- Step-by-step formula
ROI Calculator
Calculate return on investment with annualised and total returns.
- Total & annualised ROI
- Absolute gain/loss
- Formula breakdown
Savings Calculator
Calculate how your savings grow with regular deposits and interest.
- Monthly deposits
- Stacked growth chart
- AER compounding
Investment Calculator
Project long-term investment growth with fees and contributions.
- Fee impact analysis
- With vs without fees chart
- Monthly contributions
Dividend Calculator
Project dividend income with reinvestment and growth modelling.
- DRIP modelling
- Dividend growth
- Yield on cost tracking
Ratio Calculator
Simplify, scale, and solve ratios and proportions.
- Simplify any ratio
- Scale & solve
- Percentage conversion
Capital Gains Tax Calculator
Estimate CGT on shares, property, and other assets.
- UK & US rates
- Property vs shares
- Annual exemption
EBITDA Calculator
Calculate EBITDA and margin from revenue or net income.
- Two calculation methods
- EBITDA margin
- Waterfall breakdown
Income Tax Calculator UK
UK-specific income tax with 2025/26 bands and Scottish rates.
- 2025/26 tax bands
- Scotland supported
- NI & student loans
Leverage Calculator
Calculate leverage ratio and see risk amplification.
- Leverage ratio
- Margin requirement
- Risk amplification table
Margin Calculator
Calculate profit margin and markup percentages.
- Margin vs markup
- Profit per unit
- Industry benchmarks
Capital Gains Tax UK Calculator
UK-specific CGT with share pooling and reliefs.
- 2025/26 UK rates
- Loss offsetting
- Share pooling guidance
Inflation Rate Calculator
Calculate annualised inflation between two price points.
- Annualised rate
- Total increase
- Purchasing power change
Perpetuity Calculator
Calculate the present value of flat and growing perpetuities.
- Flat & growing
- Sensitivity table
- DCF terminal value
Correlation Calculator
Calculate Pearson correlation between two data series.
- Pearson r & R²
- Strength labelling
- Data paste input
Inheritance Tax Calculator
Estimate UK IHT with nil-rate bands and reliefs.
- NRB & RNRB
- Spouse transfers
- Charitable rate
Estate Tax Calculator
Estimate US federal estate tax or UK IHT.
- US & UK
- Spousal portability
- Exemption tracking
Pension Calculator
Project pension pot growth with tax relief and employer match.
- Tax relief boost
- Employer matching
- Retirement income estimate
Bond Calculator
Calculate bond price, yield, and cash flow schedule.
- Bond pricing
- Current yield
- Cash flow schedule
Retirement Calculator
Plan retirement with two-phase accumulation and drawdown.
- Shortfall analysis
- Income projection
- Two-phase planning
Portfolio Calculator
Analyse portfolio allocation and diversification.
- Weight analysis
- Concentration score
- Asset class breakdown
Options Calculator
Calculate options profit, loss, and breakeven.
- Calls & puts
- Breakeven analysis
- P&L table
FIRE Calculator
Calculate your path to financial independence.
- FIRE number
- Savings rate
- Coast FIRE
DCF Calculator
Value a company from its projected free cash flows and discount rate.
- Projection & terminal value
- WACC discounting
- Fair value per share
WACC Calculator
Find the weighted average cost of capital — the discount rate for a DCF.
- Cost of equity & debt
- Capital structure weights
- After-tax cost of debt
CAPM Calculator
Estimate required return from the risk-free rate, beta, and equity risk premium.
- Cost of equity
- Beta sensitivity
- Equity risk premium
Intrinsic Value Calculator
Value a share with Graham's revised intrinsic-value formula.
- Graham revised formula
- Growth & bond-yield inputs
- Fair value estimate
Graham Number Calculator
Work out the classic Graham number from earnings and book value per share.
- EPS & BVPS inputs
- Defensive-investor ceiling
- Price comparison
Margin of Safety Calculator
Compare intrinsic value to market price and size your margin of safety.
- Discount to fair value
- Target buy price
- Value-investing guardrail
Book Value Per Share Calculator
Calculate book value per share from equity and shares outstanding.
- Tangible book value
- Price-to-book
- Graham number input
Dividend Discount Model Calculator
Value a share from its dividends with the Gordon growth model.
- Gordon growth model
- Required-return sensitivity
- Fair value per share
Dividend Yield Calculator
Calculate dividend yield, yield on cost, and annual income.
- Yield & yield on cost
- Annual income
- Payout comparison
Volatility Calculator
Measure annualised volatility from a series of returns.
- Annualised standard deviation
- Daily/monthly inputs
- Risk comparison
Variance Calculator
Calculate sample or population variance from a data set.
- Sample & population
- Step-by-step working
- Standard deviation
Covariance Calculator
Measure how two assets move together.
- Paired data input
- Sample & population
- Correlation link
Portfolio Beta Calculator
Calculate value-weighted portfolio beta against the market.
- Value-weighted beta
- Market sensitivity
- CAPM expected return
Alpha Calculator
Calculate Jensen's alpha — return above the CAPM benchmark.
- Jensen's alpha
- Benchmark comparison
- Risk-adjusted skill
Calmar Ratio Calculator
Divide annualised return by maximum drawdown.
- Return vs max drawdown
- Worst-case risk view
- Formula & definition
Efficient Frontier Calculator
Plot the risk-return trade-off across candidate portfolios.
- Risk-return frontier
- Optimal weights
- Markowitz method
Modern Portfolio Theory Calculator
Build a mean-variance optimal allocation from your holdings.
- Mean-variance optimisation
- Minimum-variance portfolio
- Weight output
Sector Allocation Calculator
See your sector weights and spot concentration risk.
- Sector weights
- Concentration score
- Rebalancing view
New
Portfolio Rebalancing Calculator
See drift against your target weights and the exact trades to get back on track.
- Drift vs target in pp
- Buy/sell trade list
- Contribution-only mode
New
Lifetime ISA Calculator
Project your LISA to age 60 or a first home, and see what an early withdrawal costs.
- 25% bonus year by year
- Withdrawal charge modelled
- First home or age 60
Full Portfolio Analytics
Want deeper portfolio insights?
ARIA analyses your entire portfolio with institutional-grade risk management, position sizing, and optimisation. Import your broker transactions and see the difference.
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