Estimate the fee a payment processor deducts from a transaction, using a percentage rate plus a fixed per-transaction fee.
How it works
The formula is fee = amount × (rate ÷ 100) + fixed fee. A $100 transaction at 2.9% + $0.30 comes to a $3.20 fee.
What this does not include
2.9% + $0.30 is a commonly cited standard rate as of this writing, not a guarantee of any specific processor’s current pricing — rates vary by processor, country, account type, and card type, and change over time. Always check your specific processor’s current published rate.
How to use this calculator
- Enter the transaction amount.
- Enter your processor’s percentage rate and fixed fee.
A worked example
A $100 payment at PayPal’s standard 2.9% + $0.30 fee: fee = (100×0.029)+0.30 = $3.20.
A $250 payment at the same rate: fee = $7.55.
What the variables mean
| Variable | Meaning |
|---|---|
| Amount | Transaction amount |
| Rate | Percentage fee |
| Fixed fee | Flat per-transaction fee added on top of the percentage |
Edge cases worth knowing
The fixed fee makes small transactions proportionally more expensive. The $0.30 flat fee is a much bigger percentage bite on a $10 sale than on a $250 sale, which is why processing fees hit small transactions hardest as a share of revenue.
A missing transaction amount makes the fee calculation impossible, so the calculator declines to show a result without it.
Why do payment processors charge both a percentage and a fixed fee?
The percentage covers costs that scale with transaction size (like fraud risk and card network fees), while the fixed fee covers the roughly constant cost of simply processing any transaction regardless of its size.
Why do larger transactions have a lower effective fee rate?
Because the fixed fee portion matters less as a percentage of a larger transaction — a $0.30 fixed fee is 0.3% of a $100 transaction but only 0.03% of a $1,000 transaction.
Do international transactions typically cost more?
Often yes — many processors add a currency conversion or cross-border fee on top of their standard domestic rate, which this calculator doesn’t include by default but can be approximated by raising the rate field.
