Reverse fee calculator
Enter what you want to keep and any percentage plus fixed fee, and this calculator returns the amount to charge. It publishes no rates: the figures come from the rate you enter. Updated 5 September 2026.
No published fee schedule sits behind this page. Every figure below is worked out from the rate you enter. Page updated .
Showing the $100.00 example until you type an amount.
Showing the 2.9% + $0.30 example until you change it.
- Percentage of the amount
- $3.00
- Fixed fee
- $0.30
- Total fees
- $3.30
- Effective rate
- 3.19%
How this is worked out
The percentage is taken from the amount and rounded half-up to the smallest unit of the currency; the fixed fee is added whole. What you keep is the amount less the two. Reverse runs the same arithmetic backwards and reports the smallest amount to charge that still leaves you what you asked for.
To keep $100.00 at 2.9% + $0.30, charge $103.30. The fee is $3.30.
| You charge | $103.30 |
|---|---|
| Percentage of the amount | $3.00 |
| Fixed fee | $0.30 |
| Total fees | $3.30 |
| You keep | $100.00 |
| Effective rate | 3.19% |
Net to gross, not gross to net
A reverse fee calculation answers one question: I want to end up with this much, so what do I have to charge?
The intuitive move is to add the fee to the amount you want, and it does not work. Say you want to keep $100 and the rate is 2.9% plus 30 cents. The fee on $100 is $3.20, so you bill $103.20 — but the fee on $103.20 is $3.29, and you keep $99.91. You are nine cents short. The gap widens with the rate: at 20 percent it is four dollars, not nine cents.
The formula, and why this page does not use it
Charging an amount G at a rate of p plus a fixed fee f leaves you G minus (pG + f). Set that equal to your target N and solve, and you get G = (N + f) divided by (1 − p).
This page does not use that formula. It searches instead: it looks for the smallest amount to charge whose fee, rounded the way a real fee is rounded, leaves exactly your target. The two agree almost always, and where they differ the search is right, because the closed form ignores rounding and a real fee is a whole number of cents. The same search runs behind the reverse mode of every platform calculator on this site, which is why the answers agree.
When two prices leave the same amount
Sometimes there is no single exact answer. Because each fee is rounded to a whole cent, two neighbouring prices can leave you with the same net, and one cent more can leave you a cent more than you asked for. The calculator returns the lower of the two: the smallest amount that still meets your target.
Who pays the difference
Passing a fee to the customer is a commercial decision and, in some places, a legal one. Surcharging card payments is restricted or banned in several countries and under several card network rules, and adding a processing fee line to an invoice is not the same thing as raising your price. This page does the arithmetic. It does not tell you which of those you are allowed to do.
Every platform's reverse mode
If the fee you are reversing belongs to a platform on this site, use that platform's calculator: switch it to reverse and the rate is already filled in, quoted from the platform's official pricing page and dated. The list below links each one straight into reverse mode.
Frequently asked questions
Why can't I just add the fee to the amount I want?
- Because the fee is charged on what you bill, not on what you wanted to keep. Add the fee on your target and you bill a larger amount, which carries a larger fee, which leaves you short by the difference. The shortfall is small at a low rate and large at a high one, and a reverse calculation removes it by solving for the amount to charge rather than adding to the amount to keep.
What is the formula for net to gross?
- For a rate of p as a decimal plus a fixed fee f, the amount to charge for a target net of N is (N + f) divided by (1 − p). This page does not use that formula directly: it searches for the smallest amount whose fee, rounded to the currency's smallest unit, leaves exactly N. Where the two disagree by a unit, the search is the one that matches what you will actually be paid.
Does every calculator on this site have a reverse mode?
- Yes. Every platform calculator has the same forward and reverse toggle, running that platform's own published fees rather than a rate you type. The list on this page links each one straight into reverse mode, which is faster and more accurate than entering the rate by hand, because it also covers the fees a single percentage cannot express.
Can I charge the fee to my customer?
- Sometimes, and it depends where you are and how you take payment. Surcharging card payments is restricted or banned in several countries and under several card network rules, and adding a processing fee line to an invoice is not the same thing as raising your price. This page does the arithmetic; whether you are permitted to pass the fee on is a question for your own rules and your card agreement.
Why is the answer sometimes a unit off the formula?
- Because fees are whole cents, not fractions. Rounding means two neighbouring prices can leave you with the same net amount, so an exact target may have more than one answer, or an answer that leaves you a cent over. The calculator returns the smallest amount that still meets your target, which is the answer that costs you least.
Cite this page
Everything above is worked out from the rate you entered, not from any provider’s published schedule. Check that rate on your own contract or statement before you rely on it. See the methodology and the disclaimer.
Cite this page
Fees.tools. "Reverse fee calculator". https://fees.tools/reverse-fee-calculator. Page updated 2026-09-05. No fee data: figures come from the rate the reader enters.APA: Fees.tools. (2026). Reverse fee calculator. Retrieved 2026-09-05, from https://fees.tools/reverse-fee-calculator