Buyer's Premium Calculator
A buyer's premium is a percentage added to the hammer price — win a lot at $100 with an 18% premium and you owe $118 before sales tax, which in most U.S. states applies to the premium too. Use this to see your true total, or flip to reverse mode to turn an all-in budget into your maximum hammer bid.
- Hammer price
- $250.00
- Buyer's premium (18%)
- $45.00
- Sales tax (7% on subtotal)
- $20.65
- You actually pay
- $315.65
Is sales tax charged on the buyer's premium?
In most U.S. states, yes — tax applies to the full purchase price including the premium. This calculator taxes the subtotal; check your state and the auction's terms.
What's a typical buyer's premium?
10–25% depending on the house and category. Online-only auctions commonly charge 15–18%; premium fine-art houses can run 25%+ on lower tiers.
Selling instead of bidding? Try the Consignment Payout Calculator or the Cataloging ROI Calculator.
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