Free Business and Freelance Calculators

The arithmetic that decides whether a business is actually profitable rarely happens in an accounting package. It happens on the back of an envelope while you are quoting a job, setting a rate, or working out what a payment processor left you with. These pages do that arithmetic properly, grouped by the decision you are trying to make.

Rates & Pricing 9

Day rates, blended rates, utilisation, overheads, retainers, milestones and meeting cost.

Profit & Growth 11

Break-even, margin, discounts, LTV, CAC, MRR, runway and spend audits.

Invoicing & Payments 5

Invoice generator, due dates, late-payment interest, Stripe and PayPal fees.

Tax 4

VAT splitting, reverse charge, tax set-aside and sole trader vs limited company.

How the business tools are organised

Rates & Pricing is for the moment before the work starts. A freelance day rate built up from the income you need and the days you can actually bill; a blended rate across a team; an overhead rate that tells you what an hour really costs; surcharges, retainers, milestone splits and the price of a meeting. Every one of these starts from the same question — what do I have to charge for this to work? — and shows the working.

Profit & Growth is for judging whether the numbers hold once the work is under way. Break-even in units and in advertising spend, the difference between margin and markup, stacked discounts, a free-shipping threshold, lease cost per square foot, and the SaaS set: customer lifetime value, acquisition cost, MRR to ARR, runway and a subscription spend audit.

Invoicing & Payments covers getting paid. An invoice generator that produces a clean PDF, a due-date calculator for net terms, statutory late-payment interest, and fee calculators for Stripe and PayPal that answer the question people most often get wrong: how much do I need to charge so that the amount I want actually arrives?

Tax holds the compliance arithmetic. Splitting a gross figure into net and VAT, reverse-charge VAT on cross-border services, how much of each contractor payment to set aside for tax, and a sole-trader-versus-limited-company comparison for a given profit level.

Why the working is always shown

A calculator that gives you a number without the formula is a calculator you cannot argue with — and in business you usually need to. Each page here states the convention it uses (margin on price, markup on cost, interest simple or compound, VAT inclusive or exclusive) and lays out the intermediate steps so you can carry them into a quote, a spreadsheet or a conversation with an accountant.

Nothing you type is transmitted

Rates, revenue, payroll and tax figures are exactly the numbers you do not want in someone else's logs. Every tool in this section runs entirely in your browser: nothing is sent to a server, nothing is stored, and the pages keep working if your connection drops once they have loaded.

FAQ

Are my financial figures sent to a server?

No. Every calculator on this site runs entirely in your browser using JavaScript that ships with the page. Revenue, costs, rates and client figures never leave your device, are never logged, and are discarded when you close the tab.

Why does adding the processor's fee back on top come up short?

Because the fee is charged on the final amount, not the original. If you add 2.9% to $100 you get $102.90, but the fee on $102.90 is $2.98, so you land short. The correct method divides by one minus the rate after subtracting the fixed fee, which the fee calculators do for you.

Should I use margin or markup when pricing?

Price using markup, because it starts from the cost you actually know, but report and target margin, because that is what percentage of revenue you keep. A 50% margin requires a 100% markup, so stating one and applying the other is the most common and most expensive pricing error.

How accurate are these for tax purposes?

They are accurate arithmetic, not tax advice. Rates, thresholds and statutory interest change, and treatment varies by jurisdiction and by your own circumstances. Use these to understand and check a figure, then confirm anything that goes on a return with an accountant.

Do the tools work offline?

Yes, once the page has loaded. The logic is part of the page rather than a call to an API, so calculations keep working if your connection drops. Only the initial load needs a network.