Work out the true cost of auction lots on BidSpotter & i-bidder, plus eBay and Amazon resale fees and profit.
Users
7
+2 in 30 days
Rating
0.0 / 5
unchanged in 30 days
Ratings
0
0 in 30 days
Store rank
#223K
#186K among extensions
Version
2.2.0
updated 11 Jul 2026
Users
monthly, 3 months
Latest, 15 Oct 2026:7 usersMove the mouse over the chart for any month
Ratings count
monthly, 3 months
Latest, 15 Oct 2026:0 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About Auction Bid Calculator
The hammer price is only half the story. Commission, VAT and fees quietly add 20–30% to every auction win — and most bidders only find out after they've won.
Auction Bid Calculator is a sidebar that opens right on the lot page and shows your all-in cost before you bid, plus what the lot is really worth if you resell it on eBay or Amazon.
🔨 TRUE AUCTION COST — FREE, UNLIMITED
• Hammer price + commission + VAT + per-unit maths, computed live as you type
• Commission % read automatically from BidSpotter and i-bidder lot pages
• Know your walk-away number before bidding opens
🏷️ EBAY FEE & PROFIT ENGINE — FREE, UNLIMITED
• The full UK fee table: tiered final value fees by category, fixed order fees, regulatory fee, seller levels, international rates
• Private and business seller modes, VAT-registered or not
• Break-even analysis and 10/20/30/50% profit targets
• Fee rates update from our servers — always current, no extension update needed
📦 AMAZON RESALE CHECK — 10 FREE/MONTH, UNLIMITED ON PRO
• Type an ASIN, get live FBA fees, referral rates and the 30-day average Buy Box price
• Instant net-profit and ROI verdict on flipping the lot to Amazon
• Free account includes 10 checks a month; Pro (£4.99/mo or £49/yr) is unlimited
WORKS ON
bidspotter.co.uk · bidspotter.com · i-bidder.com
HONEST PRICING
The auction and eBay calculators run entirely in your browser — free forever, no account needed. Amazon checks use live market data that costs us money per lookup, which is why those are metered. No ads, no data selling, no dark patterns — cancel Pro in two clicks.
PRIVACY, PLAINLY
Your calculations and history stay on your device. If you sign in we store your email and a monthly lookup count — nothing else. Payments are handled by Stripe; we never see card details. Full policy: https://bidcalculator.co.uk/privacy/
Auction Bid Calculator is an independent tool and is not affiliated with Auction Technology Group, BidSpotter, i-bidder, eBay or Amazon. All calculations are estimates for guidance only.
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Category: Shopping
Language: English (United Kingdom)