# Auction total-cost calculator

The hammer price is never the price you pay. Enter every amount in the currency of the sale. The tool adds the buyer's premium, sales tax and shipping to show the real total and the effective premium rate.

Use the tool on the [web page](https://auctionfinder.fyi/tools/auction-total-cost). It works without JavaScript.

## How to use it

1. Enter hammer price (winning bid).
2. Enter premium rate, first slice.
3. Enter first slice ends at.
4. Enter premium rate, second slice.
5. Enter second slice ends at.
6. Enter premium rate, third slice.
7. Enter fixed buyer fee.
8. Choose sales tax base.
9. Enter sales tax or vat.
10. Enter shipping.
11. Read the result.

## How it works

The tool does not convert currencies. Enter the hammer price, limits, fees and shipping in the currency of the sale, and every result is in that same currency.

A tiered buyer’s premium charges a different percent on each slice of the hammer price. Buyer’s premium = first slice × first rate + second slice × second rate + third slice × third rate, plus any fixed buyer fee.

Enter each slice limit as a hammer price, with the rate the house publishes for that slice. For a flat premium, set the first rate and leave the other fields as they are.

Example from Christie’s published schedule for London and New York: 28% up to £1.5M or $2M, 22% to £6M or $8M and 15% above. Enter 28, 2000000, 22, 8000000 and 15 for a sale in dollars.

Sales tax is applied to the hammer price, or to hammer price plus premium, depending on the tax base you choose.

Total = hammer price + buyer’s premium + sales tax + shipping. Effective premium rate = (total − hammer price) ÷ hammer price × 100.

Published premium schedules cited on this site: Christie's buyer's premium (christies.com/en/help/buying-guide-important-information/financial-information), Heritage terms and conditions (ha.com/c/ref/terms-and-conditions.zx), Sotheby's premium help page (help.sothebys.com) and Catawiki's Buyer Protection fee (catawiki.com/en/help/fees/what-is-the-buyer-protection-fee).

Premium ranges in the summary come from the buyer_premium_pct values on the listings, which hold each house's first-slice rate; a figure appears only where the house publishes one.

> Planning figures only, not financial or legal advice. Rates, tiers, taxes and fees change; read the house's own terms before you bid. Beware of auction fraud and shill bidding — never wire money or pay by gift card to a seller you cannot verify.

> **Not financial advice.** auctionfinder.fyi is a directory, not an auctioneer, an appraiser or a financial or legal adviser. A listing is not a recommendation. Buyer's premiums, bidding rules and payment terms come from the source named on each listing and were last checked on the date shown; they change, so confirm them with the house or program before you bid or pay. Beware of auction fraud and shill bidding: never wire money or pay by gift card to a seller you cannot verify, and walk away when a price is run up by a bidder who never buys. To report a mistake, write to hello@auctionfinder.fyi.