What is a gross-up calculation for credit card fees?

A gross-up calculation determines the total amount to charge a customer so that after the credit card company deducts its processing fees (and any VAT on those fees), you receive exactly the original invoice amount.

What is the gross-up formula for credit card fees?

The formula is: Amount to charge = (Invoice + Flat fee) ÷ (1 − Effective rate), where Effective rate = CC processing fee % × (1 + VAT on fee %).

Why can't I just add the credit card fee percentage on top of my invoice?

Because the credit card company charges its percentage fee on the entire amount charged — including the surcharge you added. The gross-up formula solves this by working backwards.

Gross‑Up Calculator

Calculate exactly what to charge so you receive the full amount after credit card processing fees.

Learn how it works

Language

Country / Region

Amount you want to receive (VAT‑inclusive)

Processing fee (%)

VAT on fee (%)

Flat per‑transaction fee (e.g. Stripe's fixed charge)

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Amount to charge

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How this works

You can't just add the fee percentage on top of your invoice — the CC company charges fees on the total amount including the surcharge itself. This creates a circular problem.

The solution is to “gross up” using this formula:

charge = (base + flat) ÷ (1 − rate)

Where rate = processing fee × (1 + VAT on fee). The flat per‑transaction fee is added to the base first, then the percentage is grossed up around the combined amount.

What Is a Gross‑Up Calculation?

The problem with passing on CC fees

When a business wants to pass credit card processing fees on to a customer, the instinct is to simply add the fee percentage on top of the invoice. But this doesn’t work — the card processor charges its fee on the total amount, including the surcharge you just added.

A gross‑up calculation solves this circular problem by working backwards from the desired net amount to find the exact total that, after fees are deducted, leaves you with the original invoice amount.

Why simple addition doesn’t work

Say your invoice is 10,000 and the CC fee is 3%. If you charge 10,300 (adding 3%), the processor takes 3% of 10,300 = 309 — leaving you with only 9,991. You’re still short.

The shortfall happens because the fee applies to the total including the surcharge. Each time you add more, the fee grows too. The gross‑up formula accounts for this by dividing instead of adding.

The gross‑up formula

The core formula uses division to reverse the fee deduction:

charge = (invoice + flat fee) ÷ (1 − effective rate)

The effective rate combines the processing percentage and any VAT charged on the fee: effective rate = CC % × (1 + VAT‑on‑fee %). If there’s no VAT on the fee, the effective rate is simply the CC percentage.

Worked example

Invoice: 10,000. CC fee: 3%. VAT on fee: 7%. Flat fee: 0.

Effective rate = 3% × (1 + 7%) = 3% × 1.07 = 3.21%
Charge = 10,000 ÷ (1 − 0.0321) = 10,000 ÷ 0.9679 = 10,331.64
CC fee: 10,331.64 × 3% = 309.95. VAT on fee: 309.95 × 7% = 21.70.
After deductions: 10,331.64 − 309.95 − 21.70 = 10,000.00 ✓

When do you need a gross‑up?

Hotels and hospitality — passing card surcharges to guests while quoting a clean room rate.
Freelancers and consultants — ensuring you receive the full project fee after payment platform deductions.
B2B invoicing — recovering the exact cost of accepting card payments from clients.
E‑commerce — pricing products to absorb gateway fees without cutting into margins.

Common mistakes to avoid

Don’t forget VAT on the fee. In many countries, the processor charges VAT on top of the processing fee. This increases the effective rate.
Include the flat per‑transaction fee. Most processors charge a fixed amount per transaction (e.g. $0.30) in addition to the percentage.
Check local regulations. Some jurisdictions limit or prohibit surcharging customers for card payments. Verify the rules in your country before adding surcharges.

Quick cheat‑sheet for a basic calculator

Find the charge amount: type the invoice amount, press ÷, type 0.9679 (that’s 1 − your effective rate), press =. For a 3% fee with no VAT, divide by 0.97.
Get the effective rate first: type the CC fee % as a decimal (e.g. 0.03), press ×, type the VAT‑on‑fee multiplier (e.g. 1.07 for 7%), press =. Subtract the result from 1 to get your divisor.
Skip the % button. It works differently on every calculator. Instead, always type rates as decimals — 3% is 0.03, 7% is 0.07. This way the formula works the same on any calculator.