Add Stripe Processing Fee to Charge using ColdFusion / CFML

add-stripe-processing-fee-to-charge.cfm

<cfscript>
// 2023-02-09 Add Stripe Processing Fee to Charge (ColdFusion / CFML)
// https://support.stripe.com/questions/passing-the-stripe-fee-on-to-customers
// The amounts are calculated based on the US Stripe fee of 2.9% + $0.30 per transaction
numeric function addProcessingFeeToAmount(required numeric amount, numeric fixedFee=0.30, numeric percentageFee=0.029) hint="I add a processing fee to a charge amount" {
    return javacast("double", numberformat((arguments. Amount + arguments.fixedFee)/(1 - arguments.percentageFee), '0.00'));
}

newCharge = addProcessingFeeToAmount(1000); // 1030.18

</cfscript>