Reverse Fee Calculator for Digital Products

The two steps, and the one everyone gets wrong

If a platform charged a flat percentage and nothing else, the arithmetic would be one line. You want to keep $30, the fee is 5%, so you charge $31.58 rather than adding 5% to 30. Adding the percentage to your number is the mistake, and it is the mistake that shows up as a few dozen dollars missing at the end of the month.

Adding 5% to a $30 target gives $31.50. The platform then takes 5% of $31.50 — which is $1.575 — plus the 50 cent fixed fee, leaving you $29.43. You are 57 cents short on every single sale. Solve it properly and the number is $32.11, because the fee has to be covered by the higher price, not by the price you started with.

Then the merchant-of-record wrinkle: the fee base includes tax

This is where the general-purpose reverse calculators stop being useful. They were built for freelancers invoicing a client through Stripe, where there is no VAT line. When you sell a digital product through a merchant of record, the platform is the legal seller, it adds the buyer's local tax at checkout, and it takes its percentage from that larger total.

Lemon Squeezy documents this directly: its fee is 5% plus 50 cents per transaction, calculated on the total order value including any tax collected. Its own worked example is a $20 sale to a buyer in France. With 20% VAT added the order total is $24.00, the fee comes to $2.06, and the seller nets $17.94. The VAT was never the seller's money, so it does not reduce the net — but it does inflate the fee base, and that is the part people miss.

In numbers a solo developer can feel: on a $30 net target with a 20% VAT buyer and Lemon Squeezy's international surcharge, ignoring the tax in the fee base underprices you by about 46 cents. With a $49 price it is closer to 75 cents. Multiply by every European sale you will ever make.

Paddle and Polar quote the same way — a percentage of the checkout transaction — but only Lemon Squeezy spells out in writing that tax is part of that total. If your provider deducts from the pre-tax subtotal instead, untick the box in Advanced and the calculator follows your reading of your own contract.

Surcharges stack, and they stack on the higher number too

Lemon Squeezy adds 1.5% for cards issued outside the US, 1.5% for PayPal and 0.5% for subscription payments. A French subscriber paying by PayPal is not a 5% customer, they are an 8.5% customer plus 50 cents. Those are checkboxes in the calculator because whether they apply to you depends on who buys and how they pay — and it is worth running your real mix once rather than guessing.

Stripe has the same shape: 2.9% plus 30 cents domestically, then 1.5% for an international card and another 1% if the currency has to be converted. The headline rate is the best case, not the average.

The 50 cents is what kills cheap products

A percentage fee is survivable at any price. A fixed fee is not, because it does not scale down. At Lemon Squeezy's domestic 5% + 50 cents, here is what the fee actually takes:

This is the argument against a $5 product that has nothing to do with demand. A third of your margin goes to a fixed fee before anyone has charged back a card. Two $9 products are worse than one $19 product for the same revenue, and the calculator makes that visible in one number: the effective rate line.

What the result deliberately leaves out

A calculator that quietly ignored the rest of the cost surface would be worse than no calculator. Not in the model: payout fees (Lemon Squeezy charges 1% to non-US bank accounts, and 50 cents to a US PayPal account), refunds (the platform fee is generally not returned), chargeback fees (around $15 at both Stripe and Lemon Squeezy), affiliate commissions (3% on referred sales at Lemon Squeezy) and abandoned-cart recovery percentages. If you use any of those, put the per-sale cost in the Advanced field.

Tax is the other thing no single number can capture. The buyer's location sets the rate, so a worldwide store has no one tax figure. The sensitivity table shows what happens across 0% to 25% on the price you just calculated, which is usually a more useful picture than a single guess.

Before you commit the number

If you are still choosing the price rather than the platform, the more useful exercise is working out what your product is worth first, then using this page to check what actually lands in the bank. And if the tax question is the one you are stuck on — whether to hand it to a merchant of record or file it yourself — that trade-off is its own decision, with its own real numbers.

Running a discount? Remember that a 30% code cuts the price but not the fixed fee, so the effective rate on a discounted sale is higher than on a full-price one. The Black Friday discount setup covers the timing side of that; this page covers what the discount leaves you.

Once the price is set, the next question is whether the checkout can take the money at all — wiring Lemon Squeezy into a static Astro site is the shortest version of that path, and if Stripe will not onboard you, the fee structure you are calculating against changes entirely.