Buyer's Premium Calculator
The bid is never the price. Most auctions add a buyer's premium, and many add sales tax on top. Enter your bid to see what you will actually pay, the true auction fee included.
You actually pay
$0.00
What is a buyer's premium?
A buyer's premium is a fee the auction house charges the winning bidder, calculated as a percentage of the hammer price. At government and surplus auctions it commonly runs 10 to 18 percent. On a $1,000 winning bid, a 15 percent premium adds $150 before any tax.
Sales tax, where it applies, is usually charged on the bid plus the premium, so it compounds. Always read the auction terms for the exact premium and tax rules, since they vary by platform and by state.
Typical premiums by platform
| Platform | Typical buyer's premium |
|---|---|
| GovDeals | 0 to 12.5%, set per seller |
| GSA Auctions | Typically none |
| Public Surplus | Around 10% |
| Municibid | Varies by seller |
| HiBid auctioneers | Often 10 to 18% |
Ranges are typical, not guaranteed. The premium is set per platform and sometimes per seller, so always confirm it on the listing.
Frequently asked questions
What is a typical buyer's premium at government auctions?
It commonly runs 10 to 18 percent of the hammer price, though it varies by platform and seller. Some federal auctions such as GSA Auctions charge no buyer's premium at all. Always read the listing terms.
Is sales tax charged on the buyer's premium?
In most states that collect tax on the sale, yes. Tax is usually applied to the bid plus the premium, so it compounds. The exact rule depends on the state and the auction.
How do I calculate the buyer's premium on a bid?
Multiply the hammer price by the premium percentage. A $1,000 winning bid at a 15 percent premium adds $150 before any tax, so you owe $1,150 plus tax.
Do all government auctions charge a buyer's premium?
Most do, but not all. It is set per platform and sometimes per seller, so two lots on the same site can have different premiums. Check the terms on the specific listing.