Stop guessing what you'll actually pay at auction. Calculate buyer's premium, VAT, online fees and total cost in real-time — across every auction house you bid with.
Auction rooms move fast. Calculating buyer's premium, VAT, and online fees in your head while the hammer's about to fall is a recipe for overspending.
One auction house charges differently to the next. Online platforms add their own commission. Minimum fees kick in on cheaper lots. It's a minefield.
A £500 hammer can easily become £720+ once fees and VAT are added. Many bidders only discover the real cost when the invoice arrives.
Built by auction buyers, for auction buyers. Every feature exists because we needed it ourselves.
Enter a hammer price and instantly see the full breakdown — buyer's premium, additional charges, online commission, VAT on each component, ARR, and total cost. Toggle VAT on hammer, Artist's Resale Right, and additional costs directly in the calculator.
FreeWhen a lot goes live, an auto-generated bid ladder shows the total cost at every auction increment from the low estimate upwards. Rows turn green, amber, or red based on your budget. A MAX BID marker shows your ceiling. Tap any row to set your bid instantly.
FreeTap Go Live for a dedicated bidding screen. Compact lot info at the top, the bid ladder filling the screen, and Won/Lost/Pass buttons fixed at the bottom. Tap any ladder row to set your bid. Auto-advances when you close each lot. Auto-ends when all lots are done.
FreePaste any auction lot URL and we'll extract the data where possible — lot number, description, estimate, image, and bidding platform. Where we can't extract the data automatically, you can add it manually. Supports the-saleroom.com, EasyLive, Archives International, Iconic Auctioneers, and many more.
FreeSave each house's fee structure — BP%, additional premium, online fee, minimum buyer's fee, VAT rate, and mode. Set custom bidding increments per house (standard, fine art, fixed £1/£5/£10, or your own table). Always verify fees against the sale T&Cs before bidding.
1 house free Unlimited with ProEach lot can override the auction house defaults. Toggle VAT on hammer for lots not under the margin scheme, add Artist's Resale Right (UK or EU sliding scale), and enter additional costs like storage, shipping, or import duties.
FreeSet a budget per lot and watch the colour change in real-time. Green when safe, amber near your limit, red when you're over. Never accidentally overspend.
FreeHave a budget? Enter the maximum price you want to pay and see the budget max hammer you can bid to. Works backwards through all fees, VAT, ARR, and additional costs to give you your ceiling.
FreeCreate named sales, track lot statuses with progress bars, see won totals per currency, and archive completed sales. Each sale shows auction houses, fee flags, and a full status breakdown at a glance.
1 sale free Unlimited with ProYour data syncs in real-time via the cloud. Set up lots on your laptop, track bids on your phone. Works offline too — syncs when you reconnect.
FreeAfter the sale, print a detailed summary, export to CSV for spreadsheets, or email yourself a receipt of won lots with full cost breakdowns.
ProRuns in your browser — nothing to install. Works on iPhone, Android, iPad, laptop, desktop. Designed mobile-first for use in the saleroom.
FreeSet up in under two minutes. No card required for the free plan.
Enter the fee structure — BP%, online commission, VAT rate and mode. Set bidding increments. Always verify fees against the sale's T&Cs.
Name your sale, then add lots — paste a URL to import data where possible, or enter details manually. Set budgets, estimates, and per-lot fee overrides.
The bid ladder shows total cost at every increment. Traffic light warnings keep you within budget. The calculator works both forward and reverse.
A focused bidding screen — compact lot info, the bid ladder filling the screen, and Won/Lost/Pass buttons at the bottom. Auto-advances and auto-ends.
See totals by currency, view archived sales in detail, print or email results, export to CSV, and browse your full bidding history.
A £500 hammer price at a typical UK auction house with 25% buyer's premium, 5% online fee, and 20% VAT:
The free plan gives you full functionality to try at a real auction. Upgrade when you need more.
Join thousands of auction buyers who know their true cost before the hammer falls.
Start Free — Takes 30 Seconds 🔨The Auction Bid Assistant provides estimates based on the fee information you enter. These figures are intended as a guide only and should not be relied upon as exact costs.
Auction houses may apply additional fees, charges, or taxes not accounted for in this tool, including but not limited to artist's resale rights (ARR/droit de suite), storage charges, insurance, shipping, import duties, or other levies. Fee structures can change without notice.
Auctioneersvault Ltd accepts no responsibility or liability for any discrepancy between the estimates provided by this tool and the actual costs charged by an auction house. Always confirm the full fee schedule directly with the auction house before bidding.