Irish Calculators
Business

Auction Buyer Costs and Seller Proceeds Calculator

Apply the auction's stated charges to estimate the buyer total or seller proceeds. The model uses a single commission percentage; tiered schedules and applicable tax treatment must be established separately.

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Your numbers

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Use the actual tax treatment supplied by the auction house.
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Your figures stay on this device.

How the calculation works

Work out an auction buyer's cash cost or a seller's proceeds from a hammer price and fee schedule. Supply the applicable charges yourself; the tool does not look up auction-house terms.

Buyer total = hammer + hammer VAT + premium + VAT on premium + fixed charges + shipping. Seller proceeds = hammer − commission − VAT on commission − fixed charges.

  1. Start with the hammer price

    Use the accepted bid before premiums and other charges. Distinguish taxes already included in quoted amounts from taxes that genuinely need adding.

  2. Calculate percentage charges

    Multiply hammer price by commission percentage, then apply the entered commission-tax rate. Buyer mode also adds any separately supplied hammer-price tax.

  3. Reconcile cash amounts

    Buyer mode adds commission, taxes, fixed fees and shipping. Seller mode subtracts commission, commission tax and fixed charges to show proceeds from the supplied sale.

Worked example: Buyer

Sample inputs demonstrate the method. They are not a forecast or product offer.

A €1,000 hammer price attracts €200 commission at 20% and €46 commission tax at 23%. Adding €10 fixed fees and €30 shipping gives the example buyer total of €1,286.

Transaction side
Buyer total
Hammer price
1000
Premium or commission rate (%)
20
VAT rate on commission (%)
23
Other fixed charges including their tax
10
Shipping or collection cost including tax
30
VAT rate applied to hammer price (%)
0

Expected result

Buyer total
€1,286.00
Worked example: Seller

Sample inputs demonstrate the method. They are not a forecast or product offer.

Transaction side
Seller proceeds
Hammer price
1000
Premium or commission rate (%)
15
VAT rate on commission (%)
20
Other fixed charges including their tax
20

Expected result

Seller net proceeds
€800.00

Understanding your result

Buyer cost is a budget using your fee assumptions. It does not determine the lot's tax status, import charges or contractual rounding conventions.

Seller proceeds are after the included auction charges, not profit. Original acquisition cost and separate tax on disposal are outside this calculation.

Questions you might have

Does the default commission match an Irish auction house?

No. Defaults are an editable example. Auction houses and sale categories set different charges, so use the actual conditions of the sale.

Choosing the right inputs

Transaction side
Choose buyer or seller first. Buyer costs include shipping and entered hammer-price tax; seller proceeds deduct the selling charges from the hammer price.
Premium or commission rate
Enter the single premium or commission percentage applying to hammer price. The tool does not calculate a multi-band tariff automatically.
VAT rate on commission
Supply the tax percentage on commission itself. This is separate from the buyer field for tax on hammer price.

Common mistakes to avoid

  • Do not apply commission VAT to the hammer price unless the separate hammer-tax input genuinely requires it.
  • Avoid adding fees or shipping already included within another amount, and check whether the quoted commission includes tax.

Assumptions to check

  • Use amounts in one currency and one reporting period. Results are labelled EUR; the arithmetic also works for another consistent currency.
  • Fixed charges and shipping must already include their applicable taxes. A single percentage commission is modelled; tiered schedules must be calculated separately.

Sources and method

Read our calculation and testing approach.