Freelancers, agencies, and e-commerce merchants accepting credit cards through Stripe, PayPal, or Square face percentage deductions and fixed transaction fees that reduce take-home revenue. This calculator computes exact merchant processing deductions, reveals your effective fee percentage, and performs reverse invoice calculations so you know exactly what gross figure to bill a client to clear an exact net dollar amount.

### How Payment Gateway Deductions Are Computed The calculator models merchant processor fee schedules: - **Direct Transaction Fee**: `Fee = (Transaction Amount × Rate %) + Fixed Fee`. For standard US domestic Stripe transactions, this is `2.9% + $0.30`. For PayPal standard checkout, the rate is typically `3.49% + $0.49`. - **Net Payout**: Subtracts total processor deductions from the sale: `Net Payout = Amount - Fee`. - **Effective Fee Rate**: Calculates total fee divided by gross transaction amount: `(Fee / Amount) × 100`. - **Reverse Invoice Target (Pass-Through)**: Solves for the required gross billing total so that after the processor takes its percentage and fixed fee, you receive the exact target payment: `Invoice Amount = (Target Amount + Fixed Fee) / (1 - Rate %)`.

### Worked Payment Processing Example Suppose you bill a client **$500.00** via Stripe standard card processing (**2.9% + $0.30**): - **Transaction Fee**: `($500.00 × 0.029) + $0.30 = $14.50 + $0.30 = $14.80` - **Net Payout Received**: `$500.00 - $14.80 = $485.20` - **Effective Fee Rate**: `($14.80 / $500.00) × 100 = 2.96%` - **Reverse Invoice Amount**: To receive exactly $500.00 in your bank account, invoice the client for: `($500.00 + $0.30) / (1 - 0.029) = $500.30 / 0.971 = $515.24`.

### In-Browser Financial Privacy All fee equations, margin analyses, and reverse invoice sums are calculated 100% locally in your web browser. No billing figures or client transaction details leave your device.