Auction Fee Calculator: See Your All-In Total Before You Bid

How do you calculate the total cost of an auction item?

Four pieces make up what you pay. The hammer is the winning bid. The buyer's premium is a percentage of the hammer, set by each auction house. Sales tax is charged on the hammer plus the premium. Shipping, if the lot ships, goes on last, with no tax on it in Auktia's breakdown.

Worked example: a $100 hammer at an 18% premium is $118. Sales tax of 8.25% on $118 is $9.74. Add $15 shipping and you pay $142.74, nearly 43% more than the winning bid.

Every Auktia item page lays this out line by line, before you bid:

• Current bid: the bid itself (Starting bid before any bids, Winning bid once it sells).
• Buyer's fee: the percentage the seller (auction house) adds to the bid.
• Sales tax: on the bid plus the fee, not shipping.
• Shipping: a price, Quoted after the auction, or pickup.
• You pay: the total, to the cent.

What does a $1 bid really cost?

Small bids carry the same percentages. At an 18% buyer's fee and 8.25% tax, a $1 bid is $1 plus 18 cents of fee, plus 10 cents of tax on the $1.18, for $1.28 all-in. Bids rise $1 at a time under $100, so on a $1 auction the next bid is $2, which is $2.55 all-in at those rates.

Auktia does that sum for you on every item with one line: “Next required bid is $X, $Y all-in.” It tracks the live bid, so you always know what the next click costs before you make it.

How do I work out my max bid from a budget?

Work backward from the most you'll pay all-in. Here it is with a $200 budget, $15 shipping, an 18% buyer's fee and 8.25% tax:

1. Subtract the shipping shown on the item page from your budget (nothing for pickup): $200 minus $15 is $185.
2. Multiply 1 plus the fee by 1 plus the tax rate: 1.18 times 1.0825 is 1.27735.
3. Divide what's left by that number: $185 divided by 1.27735 is $144.83.
4. Round down to a bid you can place. Bids are whole dollars or 50 cents, so $144.50, which comes to $199.58 all-in. A $145 max would cost $200.22.
5. Enter $144.50 as your max bid. Auktia bids for you one step at a time up to it, so you may win for less, and nobody sees your max.

What does the All-in pricing switch do?

The All-in pricing switch sits in the header and is off by default. With it off, item cards show the current bid, which matches the Bid button. Turn it on and every price shows all-in: the bid, buyer's fee, sales tax and shipping, worked out on the live bid.

Whichever way the switch is set, every item page shows the full breakdown and the all-in total before you bid. Sold prices follow the switch too: the winning bid with it off, all-in with it on. More in the guide to all-in pricing.

What changes auction fees from one auction to the next?

The buyer's fee is set by each seller, so the same $100 winning bid costs a different amount at different auctions; each seller page lists its buyer's fee. Texas sales tax is 6.25% state plus up to 2% local, so up to 8.25%, and Houston is 8.25%. Shipping depends on the auction's shipping mode.

If you buy to resell, a Texas resale certificate (Form 01-339) may change the tax picture; check with the Texas Comptroller or an accountant, and see Texas auction sales tax. Bidders pay Auktia nothing, so there is no platform fee to add on top.