Free calculators

Every one of these does the whole job in your browser — no account, no email, nothing held back. Each carries the formula it uses, a worked example and what it does not cover.

• Markup vs marginPrice from a target margin, or check what a price you already charge really earns.
• Construction job marginMaterials, labour, overhead and markup — and the margin the markup actually earns.
• Airbnb profitA month after fees, cleaning and consumables, with break-even occupancy.
• Rental property ROICap rate, cash-on-cash and monthly cashflow, reported separately.
• Break-evenUnits needed to cover costs, and how far sales can fall before you stop.

When one calculation turns into a list you need to keep, the spreadsheets do the same maths across everything you sell, own or quote.