UK Business and Contractor Calculators: Free Tools for 2026/27
Tax calculators for limited companies, contractors, sole traders, and small businesses.
8
Free tools
2026/27
Tax year
HMRC
Verified rates
Running a business or contracting in the UK means navigating corporation tax, IR35, dividend taxation, and the ongoing question of the most tax-efficient way to pay yourself. Our business and contractor calculators are built specifically for self-employed people, limited company directors, and contractors who need to model their total tax position - not just a simple income tax figure. From comparing inside vs outside IR35 take-home pay to calculating break-even pricing for a new product, these tools cover the financial decisions that matter most to UK business owners. All calculators use verified 2026/27 rates including the updated employer NI rate, the current £500 dividend allowance, and corporation tax marginal relief thresholds.
All Business & Contractor Calculators
8 toolsIR35 Calculator
Compare your net income inside vs outside IR35. See the true tax cost of being deemed inside IR35 at any day rate.
Contractor Take-Home Calculator
Calculate your take-home pay as a limited company contractor, comparing inside vs outside IR35.
Dividend Tax Calculator
Calculate tax on dividends from your limited company after the £500 dividend allowance for 2026/27.
Limited Company Tax Calculator
Model your total tax position as a director: salary, dividends, corporation tax, and NI combined.
Profit Margin Calculator
Calculate gross and net profit margins. Enter cost and revenue to see margin and markup percentages.
Markup Calculator
Calculate the selling price for any cost using a percentage markup. Includes margin vs markup comparison.
Break-Even Calculator
Calculate your break-even point in units and revenue. Essential for pricing decisions and business planning.
Invoice Generator
Create professional UK invoices with automatic VAT calculation, payment terms, and PDF export.
Related Guides
March 2026
IR35 Explained: Inside vs Outside and What It Means for Your Take-Home Pay
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Read guideFebruary 2026
Corporation Tax Rates 2026/27: Small Profits, Main Rate and Marginal Relief
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The Optimal Director Salary for 2026/27
Most company directors set their salary at the Secondary NI Threshold (£5,000 in 2026/27) to preserve state pension entitlement. Here's the maths.
Read guideMarch 2025
IR35 Status: How to Determine If You're Inside or Outside
The key IR35 tests are mutuality of obligation, substitution, and control. We walk through each test with real examples and explain what HMRC looks for.
Read guideJanuary 2025
Sole Trader Tax: How Self Assessment Works for Small Businesses
If you're self-employed, you pay Class 4 NI and income tax on your profits via self assessment. We walk through the whole process with worked examples.
Read guideFrequently Asked Questions
Common questions about business & contractor.
For 2026/27, the most tax-efficient approach for most directors is: a salary at the Secondary NI Threshold (£5,000/year) - enough to preserve state pension entitlement without triggering NI or income tax - plus dividends to use up the basic rate band. After corporation tax at 19-25%, dividends are taxed at 10.75% (basic rate), 35.75% (higher rate), or 39.35% (additional rate) after the £500 allowance.
The difference can be substantial. A contractor on £500/day (£115,000/year) outside IR35 taking an optimal salary-dividend mix might take home £83,000+. Inside IR35, the same income taxed as employment could yield £70,000. Our IR35 calculator gives you the exact figure based on your day rate and circumstances.
Companies with profits under £50,000 pay the small profits rate of 19%. Companies with profits over £250,000 pay the main rate of 25%. Companies with profits between £50,000 and £250,000 get marginal relief, with an effective marginal rate of 26.5% in the relief band. These thresholds are divided between associated companies.
The break-even point is where total revenue equals total costs - you're making neither profit nor loss. It's calculated as Fixed Costs divided by Contribution per Unit (where Contribution = Selling Price minus Variable Cost per Unit). Knowing your break-even point is essential for pricing decisions, assessing business viability, and planning for growth.
Sole traders pay income tax on profits above the personal allowance (£12,570), at the same rates as employees (20%, 40%, 45%). However, they pay Class 4 NI (6% on profits £12,570 to £50,270; 2% above) rather than Class 1. Class 2 is treated as paid when profits reach £7,105; voluntary Class 2 is £3.65/week below that. Sole traders can deduct allowable business expenses before calculating tax.
All calculations use official HMRC rates for 2026/27, updated April 2026. Results are estimates for guidance only - not financial advice. Our methodology · Disclaimer