Break-even Transaction Size Calculator
Find minimum transaction size to cover fees and desired margin.
With a fixed fee per transaction (e.g. $0.30), small transactions have high effective rates. To break even after fees and achieve a target margin, you need a minimum transaction size. Formula: Min = (Fixed fee) / (1 - Rate - Margin). This calculator helps you set minimum order values or bundle products to reach profitability.
Inputs
Results
Minimum transaction: $3.90
Fee at min: $0.41
Net after fee: $3.49
Insights
Formula
Min = Fixed / (1 - rate - margin) At break-even: Revenue - Fee = Revenue * margin Fee = Revenue * rate + Fixed So: Revenue - (Revenue * rate + Fixed) = Revenue * margin Revenue * (1 - rate - margin) = Fixed Revenue = Fixed / (1 - rate - margin)
Input Definitions
What does each input mean?
- Processing rate %
- Your processor's percentage fee per transaction. Stripe charges 2.9%.
- Fixed fee
- Fixed amount charged per transaction. The $0.30 fixed fee makes small transactions expensive.
- Desired margin %
- Target profit margin after paying processing fees. Minimum transaction size is calculated to achieve this.
Related Calculators
Finding the Transaction Size Where Processing Fees Stop Hurting
Payment processing fees have two components — a percentage and a fixed flat fee — and that flat fee makes very small transactions disproportionately expensive. A $2.00 sale with a $0.30 fixed fee has an effective rate of 15% before you even count the percentage. This calculator helps you find the exact transaction size where fees become a manageable percentage of revenue, so you can set pricing floors and minimum order values that protect your margins.
Use this when you’re deciding whether to set minimum purchase amounts, evaluating the profitability of low-cost digital products, or comparing different processors for a business model built on high transaction volume with small average orders. Knowing your break-even transaction size is one of the most underused pricing tools available.