Business Calculators

Calculators for the numbers that determine whether a business works: what you charge, what you keep, and how long your cash lasts.

The distinction that costs the most money

Margin is not markup. Margin is profit as a percentage of the selling price; markup is profit as a percentage of cost. A £50 item sold for £100 carries a 50 percent margin but a 100 percent markup. Confusing the two systematically underprices goods — to hit a 40 percent margin on a £60 cost you divide by 0.60 and charge £100, whereas adding 40 percent to cost gives £84 and a margin of only 28.6 percent. The Profit Margin and Pricing Calculators both make this explicit.

Knowing your floor

Break-Even divides fixed costs by contribution per unit, where contribution is price minus variable cost. Two cautions: misclassifying a cost distorts the answer badly, and if contribution is negative there is no break-even point at all — every extra sale increases the loss, and volume cannot fix it. Include a market-rate salary for yourself as a fixed cost, or you get a flatteringly low figure that has you working for nothing.

The Freelance Rate Calculator applies the same honesty to personal rates. The usual error is assuming 40 billable hours a week; after admin, marketing, proposals and unpaid research, 1,000 to 1,400 billable hours a year is realistic for a full-time freelancer.

Tracking a running business

SaaS MRR, Startup Runway, ROI, Commission and Payroll cover ongoing operations. For subscription businesses, net revenue retention — which folds in churn, downgrades and expansion — tells you more than gross churn alone. For runway, model burn growth if you are hiring, because a flat calculation against a growing team is optimistic.