Invoicing & Payment Calculators

Everything that happens between finishing the work and the money arriving comes down to a few small calculations that are easy to get slightly wrong: when an invoice is actually due, what a late payment costs, whether an early payment discount is worth taking, how to split a project fee into a deposit and milestones, and how VAT changes the total. These calculators do each of those jobs in one step, run entirely in your browser, and explain the rule they apply so you can quote it to a client.

Use them when you write the invoice, not when you chase it. A due date on the invoice in words and numbers, a late-fee clause that was in the contract, and a deposit before work starts prevent most payment problems before they happen.

• Deposit and Milestone Split CalculatorSplit a project fee into a deposit and milestone payments
• Early Payment Discount CalculatorIs 2/10 net 30 worth taking? See the saving and the implied annual rate
• Invoice Due Date CalculatorNet 30, net 60 or custom terms, with business-day and weekend handling
• Late Payment Fee CalculatorFlat fees or monthly interest on overdue invoices, prorated by day
• VAT CalculatorAdd VAT to a net price or remove it from a gross price at any rate