Profit Margin Calculator for UK Businesses

A UK profit margin calculator returns gross, operating, and net margins after VAT (20%), Corporation Tax (25% main / 19% small profits, with marginal relief between £50k-£250k), and employer NI (13.8% above £9,100). Enter VAT-exclusive revenue. HMRC's CT600 guidance and VAT Notice 700 are the authoritative references.

Margin and markup get confused constantly in UK SME finance — a 50% markup is only a 33.3% margin, and that 16.7 percentage-point gap is the difference between a healthy business and one quietly losing money on every unit sold. This calculator separates the three margin layers (gross, operating, net) using your VAT-exclusive revenue figure — the HMRC standard for accounts filed with Companies House — so you're not inflating the top line by 20% of VAT you collect on HMRC's behalf.

Costs go into two buckets. Cost of goods sold (COGS) is everything that scales with the unit sold: supplier invoices, import duty since the EU-UK Trade and Cooperation Agreement changes, freight, payment processing (Stripe, GoCardless, Worldpay), and packaging. Operating overheads are rent, payroll including 13.8% employer National Insurance above the £9,100 secondary threshold, software, professional fees, and marketing.

Realistic UK net-margin benchmarks (HMRC sector ratios + FAME small-company data): - Professional services: 12-25% - Trades and construction: 4-8% - Ecommerce: 5-12% depending on category and ad spend - Hospitality: 2-7% (London rents compress this further) - SaaS post-scale: 20%+ once customer acquisition cost normalises

If gross margin lands under 30%, you're in a high-volume model where price discipline and tight inventory turns are the strategic levers — not cost-cutting. If gross is above 60%, customer acquisition cost is the binding constraint.

The calculator also flags when your Corporation Tax estimate (using the marginal relief formula between £50,000 and £250,000 profit) suggests pulling forward capex or pension contributions before year-end. For the underlying rules, HMRC's CT600 guidance, VAT Notice 700, and the Employer Helpbook on gov.uk are the authoritative sources.