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Invoices & Payments
Work out due dates, discounts, deposits, fees and the amount you must charge to receive the intended net payment.
15 calculators · 20 practical guides
Calculators
Work out the number first
Each calculator shows the formula, the result in plain language, assumptions that can distort it and a useful next step.
Invoice Due Date CalculatorCalculate an invoice due date from the invoice date and chosen payment term.Net 15 Due Date CalculatorCalculate the calendar due date for Net 15 payment terms. The result also shows the commercial meaning and the next number to verify.Net 30 Due Date CalculatorCalculate the calendar due date for Net 30 payment terms. The result also shows the commercial meaning and the next number to verify.Net 45 Due Date CalculatorCalculate the calendar due date for Net 45 payment terms. The result also shows the commercial meaning and the next number to verify.Net 60 Due Date CalculatorCalculate the calendar due date for Net 60 payment terms. The result also shows the commercial meaning and the next number to verify.Late Payment CalculatorCalculate a simple late charge using outstanding balance, annual rate and days overdue.Early-Payment Discount CalculatorCalculate the cash received and discount cost when offering an early-payment percentage.Payment Processing Fee CalculatorCalculate processing fees from a percentage rate plus fixed transaction fee.Reverse Payment Fee CalculatorCalculate the amount to charge so the net received matches your target after percentage and fixed processing fees.Amount to Charge CalculatorCalculate a gross charge required to receive a target net amount after processing fees.Invoice Discount CalculatorCalculate the reduced invoice amount and revenue given up after a discount.Project Deposit CalculatorCalculate a project deposit from total contract value and deposit percentage.Milestone Payment CalculatorCalculate a milestone payment from contract value and milestone percentage.Retainer Deposit CalculatorCalculate an upfront retainer deposit from the agreed retainer value. The result also shows the commercial meaning and the next number to verify.Stripe US Domestic Card Fee CalculatorEstimate the standard Stripe US domestic online card fee using the currently published 2.9% + 30¢ standard rate.
Guides
Understand the decision behind the formula
How to Calculate an Invoice Due DateStart from the invoice date and stated payment term, then account for contract-specific business-day rules if they apply.What Does Net 30 Mean?Understand Net 30 as a contractual payment term and calculate the due date consistently.Net 15 vs Net 30Compare how shorter payment terms affect the calendar due date and cash collection timing.Net 45 Payment TermsCalculate the due date and make the term explicit on the invoice and agreement.Net 60 Payment TermsUnderstand the longer collection window created by Net 60 terms. Use the formula consistently and keep the assumptions visible before making a pricing or payment decision.How to Calculate a Late Payment ChargeCalculate simple interest only when your contract and applicable rules allow the stated charge.Early-Payment DiscountsMeasure the cash cost of a discount before using it to accelerate payment.Payment Processing Fee MathCalculate percentage plus fixed transaction fees without relying on provider-specific assumptions.How to Reverse-Calculate a Processing FeeGross up a charge when you need to receive a target net amount after fees.How Much Project Deposit Should You Request?Use cash-flow risk, committed capacity and direct costs to choose a deposit structure.How to Structure Milestone PaymentsTie payments to clear deliverables or stages rather than vague percentages alone.Retainer Deposits and Upfront PaymentsSeparate an upfront deposit from the recurring service amount and clearly define how it is applied.How Invoice Discounts Affect RevenueCalculate both the reduced receipt and the amount of revenue surrendered.Stripe US Standard Card Fee CalculationUse Stripe’s currently published standard US domestic online-card rate and verify pricing before relying on it.Charging Clients for Payment FeesCalculate the math separately from whether passing fees to customers is contractually or legally permitted.Payment Terms Checklist for Service BusinessesMake due date, deposit, milestones, late terms and payment method clear before work begins.Invoice Cash Flow vs Project ProfitA profitable project can still create cash pressure when payment arrives long after costs are incurred.Deposit vs RetainerUse precise contract language because an upfront deposit and a recurring retainer can serve different purposes.Are Net Terms Calendar Days?Do not assume business-day treatment unless your agreement or applicable rule says so.Why Payment Fees Need a Verified DateProvider pricing changes by country, card type and product, so fee calculators should show source and review date.