A nightly rate is a unit price, not necessarily your stay’s total. Before adding anything, write down whether each number applies to one room, one person, one night or the entire booking. A fee described simply as “per night” needs clarification if you are booking more than one room.
Start with a clean set of inputs
- Record the number of rooms and nights. Ask whether the room rate already includes tax.
- Identify mandatory room-night fees. Multiply these by rooms and nights only when that is how the property charges them.
- Keep whole-booking charges separate. Do not multiply a once-only cleaning or administration charge by nights.
- Choose the correct taxable base. A tax percentage does not tell you which charges it applies to.
Worked example: a hypothetical two-room stay
Assume 3 nights, 2 rooms, a base rate of 80 USD per room-night, a fee of 10 USD per room-night, one booking-wide charge of 30 USD, and a 10% tax on the room price only.
Rooms: 3 × 2 × 80 = 480 USD
Nightly fees: 3 × 2 × 10 = 60 USD
Tax: 480 × 0.10 = 48 USD
Total: 480 + 60 + 30 + 48 = 618 USD
The all-in room-night cost is 618 ÷ 6 = 103 USD. None of these numbers is a current hotel price.
Avoid the double-counting trap
If the provider already quotes 618 USD inclusive of these charges, adding the 60, 30 and 48 again would overstate the cost. Use an itemized pre-tax rate in the calculator, or set already-included extras to zero and describe your own assumptions when sharing the result.
Know what the model leaves out
A refundable security hold affects available cash but is not automatically a final expense. Keep it in a separate cash-flow note. Per-person taxes, tiered rates, changing nightly prices and tax-on-tax rules do not fit a single flat percentage. Calculate those separately or ask for a written final total.
The FTC’s guidance concerns U.S. fee transparency; it is not a worldwide rule or a promise of a refund. Your practical check is the provider’s final itemized quote.
Official references
References checked 3 November 2026. Examples and arithmetic are original; booking conditions can change.