Auctioneer Commission Calculator
Net proceeds from auction after commission and fees.
About this calculator
The Auctioneer Commission Calculator splits a single hammer (final bid) price into what the seller actually takes home and what the buyer actually pays, since auction fees are charged to both sides of the transaction independently. The seller pays Seller Commission — typically 10-25% of hammer price, often on a declining scale for higher-value lots — plus Lot Fee (a flat per-lot charge for handling, photography, and catalog listing) multiplied by Number of Lots, plus Insurance as a percentage of hammer price; Seller Net Proceeds is what remains after all three deductions. The buyer, separately, pays Buyer's Premium — typically 15-25% — added on top of the hammer price, so Total Buyer Pays is always higher than the hammer price itself.
This dual-fee structure means the auction house collects revenue from both sides of the same transaction: Auction House Revenue sums seller commission, buyer's premium, and lot fees together. Effective Seller Cost expresses the total drag on the seller — commission, lot fees, and insurance combined — as a single percentage of hammer price, which is useful for comparing net proceeds across auction houses that structure their fees differently (some charge higher commission with lower lot fees, or vice versa).
Inputs
Results
Seller Net Proceeds ($)
$4,175.00
≈ 4 smartphones
Total Buyer Pays ($)
$6,000.00
≈ 6 smartphones
How to Use This Calculator
- Enter the hammer (final bid) price and the seller commission percentage (typically 10-25%).
- Input the buyer's premium percentage (typically 15-25%), per-lot fee, and number of lots.
- Set the insurance percentage if applicable.
- Review seller net proceeds and the total the buyer pays (hammer + buyer's premium).
- Check auction house revenue to understand total fees generated from the transaction.
How the result changes with Hammer Price ($)
| Hammer Price ($) | Seller Net Proceeds ($) | Total Buyer Pays ($) |
|---|---|---|
| 2,500 | $2,075.00 | $3,000.00 |
| 3,750 | $3,125.00 | $4,500.00 |
| 7,500 | $6,275.00 | $9,000.00 |
| 12,500 | $10,475.00 | $15,000.00 |
What each input means
- Hammer Price ($)
- Final bid (hammer) price of the item.
- Seller Commission (%)
- Commission charged to the seller. Typical: 10-25%.
- Buyer's Premium (%)
- Additional charge to the buyer. Typical: 15-25%.
- Lot Fee ($)
- Per-lot handling, photography, and catalog fee.
- Number of Lots
- Number of lots consigned.
- Insurance (%)
- Insurance as percentage of hammer price.
What each result means
- Seller Net Proceeds ($)
- What the seller takes home after all deductions.
- Seller Commission ($)
- Commission deducted from seller.
- Buyer's Premium ($)
- Premium added to buyer's total.
- Total Buyer Pays ($)
- Hammer price + buyer's premium.
- Total Lot Fees ($)
- All lot-related fees.
- Auction House Revenue ($)
- Total revenue for the auction house.
- Effective Seller Cost (%)
- Total cost to seller as percentage of hammer price.
How this is calculated
Worked example, using the default values
- Identify Input Parameters6 parametersHammer Price ($) = 5000, Seller Commission (%) = 15, Buyer's Premium (%) = 20, Lot Fee ($) = 25, Number of Lots = 1, Insurance (%) = 1 = 6 input(s) provided
- Calculate Seller Net ProceedsSeller Net Proceeds = hammerPrice - sellerCommission - totalLotFees - insuranceCost4175 = $4,175
- Calculate Total Buyer PaysTotal Buyer Pays = hammerPrice + buyersPremium6000 = $6,000
- Calculate Seller CommissionSeller Commission = hammerPrice * (sellerCommissionPct / 100)750 = $750
- Calculate Buyer's PremiumBuyer's Premium = hammerPrice * (buyersPremiumPct / 100)1000 = $1,000
Engine last updated . Checked against 1 independently-derived test — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why is Total Buyer Pays higher than the Hammer Price?
Total Buyer Pays is Hammer Price plus Buyer's Premium, an additional charge — typically 15-25% of hammer price — that most auction houses add on top of the winning bid. The premium is separate from the seller's commission; it's revenue the auction house collects directly from the buyer, on top of what it earns from the seller's side of the same sale.
What's included in Seller Net Proceeds?
Seller Net Proceeds is Hammer Price minus Seller Commission, minus Total Lot Fees (Lot Fee times Number of Lots), minus Insurance Cost. It does not subtract Buyer's Premium, since that charge is paid by the buyer on top of the hammer price and never touches the seller's proceeds — the seller's costs and the buyer's costs are calculated independently from the same hammer price.
How does Number of Lots affect the total cost to the seller?
Number of Lots multiplies directly against Lot Fee to produce Total Lot Fees, a flat per-lot charge for handling, photography, and catalog listing that's deducted from Seller Net Proceeds. It has no effect on Total Buyer Pays, Buyer's Premium, or any other buyer-side figure, since lot fees are a seller-side cost tied to how many items were consigned, not how much any one item sold for.
What does Effective Seller Cost (%) measure?
Effective Seller Cost is the total percentage of Hammer Price lost to seller-side costs — commission, lot fees, and insurance combined — computed as (Hammer Price minus Seller Net Proceeds) divided by Hammer Price. It's a single comparison figure for evaluating different auction houses' fee structures side by side, since two houses can charge the same headline commission percentage but different net costs once lot fees and insurance are factored in.
Related Calculators
The questions that sit next to this one — chosen by subject, including calculators filed under a different category.
Auction Commission Calculator
Calculate net proceeds from auction sales after buyer's premium, seller's commission, lot fees, and insurance.
Small BusinessSales Commission Calculator
Calculate sales commission earnings including base salary, commission rate, and quota bonuses. See total earnings and quota achievement.
Small BusinessBreak-Even Analysis Calculator
Calculate break-even point, profit analysis, and margin of safety. Essential for business planning and pricing decisions.
Small BusinessDiscount Calculator
Calculate discounted prices, savings amount, and discount percentage. Perfect for sales and pricing.
More in Business & Entrepreneurship.