Running a business requires constant financial decision-making — from pricing products and managing payroll to planning cash flow and assessing the cost of new debt. These free UK business calculators cover the full range of financial calculations a company director, entrepreneur, or finance manager needs to hand. Whether you are estimating a corporation tax bill, modelling the break-even point of a new product line, projecting 12-month cash flow, or comparing funding options for expansion, each tool is built around UK-specific rates and formulas so the outputs are directly applicable to your situation. The business section includes tools for tax planning, profitability analysis, debt assessment, strategic forecasting, startup valuation, and business performance tracking. All calculations are estimates — they are designed to inform decisions, not replace professional advice — but they provide the numerical foundation for better, faster business judgements.
Corporation tax is the primary direct tax on UK company profits. For 2026/27, the main rate is 25% for profits above £250,000 and 19% for profits at or below £50,000. Companies with profits between these thresholds pay a blended effective rate under marginal relief. Importantly, corporation tax is charged on taxable profit — which is net profit adjusted for disallowed expenses, capital allowances, and other HMRC-specific adjustments. Common adjustments include adding back depreciation (which is not tax-deductible) and substituting capital allowances (which are). Getting this calculation right before year-end allows directors to time expenditure and pension contributions to reduce taxable profit.
Profitability analysis requires understanding three distinct margins. Gross profit margin measures the profitability of the core product or service before overheads — it reflects pricing power and production efficiency. Operating profit margin (also called EBIT margin) reflects the profitability of the business operations after overhead costs but before interest and tax. Net profit margin is the final bottom-line figure after everything. A business can have a healthy gross margin but a poor operating margin if overheads are excessive — monitoring all three separately reveals where value is being eroded.
Cash flow is distinct from profit and is arguably more important for business survival. A company can be profitable on paper while running out of cash if customers pay slowly, stock is tied up in inventory, or large payments fall due in a single period. The cash flow forecast models every inflow and outflow month by month to identify periods of stress in advance. Most business failures are ultimately cash flow failures, not profitability failures — which is why lenders, investors, and sophisticated business owners prioritise cash flow planning alongside the profit and loss statement.
Debt assessment requires evaluating both the repayment cost and the coverage ratio. The monthly repayment on a business loan is determined by the loan amount, interest rate, and term. Total interest over the life of the loan can be substantial — a £100,000 loan at 7% over five years costs approximately £19,500 in interest. The Debt Service Coverage Ratio (DSCR) measures whether operating income comfortably covers those repayments. Lenders typically require a DSCR of at least 1.25 before approving commercial borrowing; a ratio below 1.0 means the business cannot service the debt from operations alone.
Startup valuation and funding decisions are two of the most consequential financial choices an early-stage founder makes. Overvaluing at seed stage can create a down-round problem later; undervaluing means giving away too much equity for the capital raised. The Startup Valuation Calculator models common valuation approaches — revenue multiples and EBITDA multiples — alongside equity dilution, so founders can enter fundraising conversations with a grounded numerical position. The Funding Comparison tool adds the cost dimension, comparing the total cost of capital across bank loans, angel investment, and equity over a defined time horizon.
Key performance indicators (KPIs) are the metrics that tell you whether your business is heading in the right direction. The most important financial KPIs include gross and net margin, monthly recurring revenue, customer acquisition cost (CAC), customer lifetime value (LTV), the LTV:CAC ratio, and customer churn rate. A healthy LTV:CAC ratio is generally 3:1 or above — meaning each customer generates at least three times the cost of acquiring them. The Business KPIs Dashboard on this page calculates all of these in a single tool so you can see your overall financial health at a glance.
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Calculate UK corporation tax at 19% or 25% with marginal relief for FY2025.
Use this tool to: estimate your annual UK corporation tax liability including marginal relief
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Find the sales volume and revenue needed to cover your fixed and variable costs.
Use this tool to: find the sales volume and revenue needed to cover all fixed and variable costs
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Calculate gross, operating, and net profit margins for your business.
Use this tool to: measure gross, operating, and net profitability at any revenue level
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Calculate employee take-home pay and total employer cost including NI.
Use this tool to: calculate employee take-home pay and total employer cost including NI
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Calculate monthly repayments and total interest on a business loan.
Use this tool to: model monthly repayments and total interest across different loan scenarios
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Build a simple 12-month cash flow projection for your business.
Use this tool to: project monthly cash inflows and outflows over a 12-month period
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Calculate the final value, total interest earned, and effective annual rate for any savings or investment using compound interest.
Use this tool to: model the growth of reinvested business funds or savings over time
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Find out how long it takes to clear your credit card and the total interest you will pay.
Use this tool to: plan how long it takes to clear high-interest business credit card debt
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Convert an annual percentage rate (APR) to an annual percentage yield (APY) for any compounding frequency.
Use this tool to: compare the true borrowing cost across loans with different compounding frequencies
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Calculate the number of units and revenue needed to hit your target profit.
Use this tool to: calculate the units and revenue needed to hit a specific profit target
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Calculate your Debt Service Coverage Ratio to assess whether income covers loan repayments.
Use this tool to: assess whether business income is sufficient to service proposed new debt
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Calculate operating cash flow from net income, depreciation, and changes in working capital.
Use this tool to: measure cash generated from core operations in any period
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Forecast your business profit and loss over multiple periods with revenue growth and cost assumptions.
Use this tool to: forecast P&L over multiple periods with revenue growth and cost assumptions
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Estimate your startup's pre-money valuation using revenue and EBITDA multiples, and calculate equity dilution.
Use this tool to: estimate pre-money valuation using revenue and EBITDA multiples
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Compare business funding options — bank loan, angel investment, or equity — side by side on cost and repayment.
Use this tool to: compare bank loans, angel investment, and equity funding side by side
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Calculate your key business KPIs — margins, churn rate, CAC, LTV, and LTV:CAC ratio — in one place.
Use this tool to: calculate and track key business performance metrics in one place