Auction Cost Calculator - Calculator Academy

Calculate total auction costs, including buyer's premium, fees, tax and shipping, with deposit shown separately, or find your maximum bid from your budget.

Solve for

Estimate total purchase cost in USD using your auction’s terms. Enter the winning bid and buyer’s premium rate.

Winning bid / hammer price ($)

Enter USD, to the nearest cent.

Buyer’s premium (%)

Enter the rate from your auction terms, including 0 if no premium applies.

Tax, services and credit (blank amounts mean zero)

Additional bidding surcharge (%)

Blank means 0%. Enter the rate from your auction terms.

Taxable amount

Use the applicable auction terms. This simplified model does not determine tax law or tax optional services.

Sales tax / VAT (%)

Blank means 0%. Enter the rate from your auction terms.

Quoted resale royalty ($)

Blank means $0. Enter the quoted amount; statutory artist resale royalties can use thresholds, tiers and caps.

Authentication fee ($)

Blank means $0.

Insurance (% of bid)

Blank means 0%. Enter the rate from your auction terms.

Shipping / transport ($)

Blank means $0.

Documentation / administration ($)

Blank means $0.

Other fixed costs ($)

Blank means $0. Include any applicable storage, imagery, broker or other charges.

Deposit / credit already paid ($)

Blank means $0.

Auction Cost Formula

The following formula gives total purchase cost when the buyer’s premium is the only additional charge. Other entered costs and tax are added separately; deposits reduce the amount still due.

AUC = SP + SP \times AF / 100

Where AUC is the total purchase cost before credit ($)
SP is the winning bid or hammer price ($)
AF is the buyer’s premium rate (%)

Multiply the hammer price by the buyer’s premium percentage over 100, then add that premium to the hammer price. In the calculator, General auction total uses your quoted rates; IAA vehicle total uses the selected published buyer and bidding fee tables plus your quoted fixed charges. Maximum-bid modes use the same cost model with entered rates and fixed quotes held constant. Confirm current fees, tax treatment and allowed bid increments with the auction.

How to Calculate Auction Cost?

The following example problems outline how to calculate Auction Cost.

Example Problem #1:

First, determine the total auction sell price ($). The total auction sell price ($) is given as 400.
Next, determine the auction fee (%). The auction fee (%) is provided as 20.
Finally, calculate the Auction Cost using the equation above:

AUC = SP + SP * AF/100

The values given above are inserted into the equation below:

Premium = 400 * 20/100 = $80; AUC = 400 + 80 = $480 before other costs or tax.

Example Problem #2:

The variables needed for this problem are provided below:

total auction sell price ($) = 600

auction fee (%) = 10

Entering these values and solving gives:

Premium = 600 * 10/100 = $60; AUC = 600 + 60 = $660 before other costs or tax.