**Auction Calculator — Buyer’s Premium, Max Bid and Consignor Net**

> The hammer price is neither what the buyer pays nor what the seller banks. Work out the all-in total, the highest bid your budget allows, and the consignor’s net.

Source: https://sportscardradar.com/tools/auction-calculator/ · updated: 2026-09-11

[Valdar](https://sportscardradar.com/) / [Free tools](https://sportscardradar.com/tools/) / Auction Calculator

# Card auction calculator: what winning costs and what consigning returns

A hammer price is neither what the buyer pays nor what the consignor banks. Put one number in and get both sides of the same lot, the house take between them, and the highest bid a budget allows.

Free · no sign-up Runs in your browser By [Merey Tleugazin](https://sportscardradar.com/story/) Updated September 11, 2026

Hammer price

$

The number the auctioneer calls. Both sides below are computed from it.

Buyer's premium

%

From the conditions of sale, not from this page.

Shipping and handling

$

Sales tax

%

Your all-in budget

$

Returns the highest hammer bid that stays inside it.

Consignor commission

%

Often zero on material a house wants.

Consignor fixed fees

$

Photography, cataloguing, insurance in transit.

Charge sales tax on the premium as well as the hammer

$1,225

all in, on a $1,000 hammer · 122.5% of the number the auctioneer called

A budget of $1,500 allows a top hammer bid of $1,229. Bidding moves in $50.00 steps at
that level, so leave your maximum on a step rather than between two.

Consignor banks$1,000100% of hammer

House take$20020% of hammer, from both sides

Bid step here$25.00the underbidder stopped $25.00 below you

| Line | Amount | Share of hammer |
| --- | --- | --- |
| Hammer price the auctioneer called | $1,000 | 100.0% |
| Buyer's premium, 20% | $200 | 20.0% |
| Shipping and handling | $25.00 | 2.5% |
| Sales tax, 0% including the premium | $0.00 | 0.0% |
| Buyer pays | $1,225 | 122.5% |
| Consignor commission, 0% | -$0.00 | 0.0% |
| Consignor fixed fees | $0.00 | 0.0% |
| Consignor banks | $1,000 | 100.0% |

The same lot costs the buyer $1,225 and pays the consignor $1,000. $200 of
that gap is the house, before shipping and tax. At a zero consignor commission the house is paid entirely by the
buyer, which is the usual arrangement on material an auction house wants. Premium and commission are both stated in
the terms of the sale you are bidding in. Read those rather than these defaults.

*Standard bid increments, and the price a maximum bid actually produces*

| Bidding band | Step | Underbidder stopped at | So you pay | All in at 20% |
| --- | --- | --- | --- | --- |
| $0 to $25 | $1 | $4 | $5 | $6 |
| $25 to $100 | $2.50 | $35 | $37.50 | $45 |
| $100 to $250 | $5 | $120 | $125 | $150 |
| $250 to $500 | $10 | $290 | $300 | $360 |
| $500 to $1,000 | $25 | $600 | $625 | $750 |
| $1,000 to $2,500 | $50 | $1,200 | $1,250 | $1,500 |
| $2,500 to $5,000 | $100 | $2,900 | $3,000 | $3,600 |
| $5,000 to $10,000 | $250 | $6,000 | $6,250 | $7,500 |
| $10,000 to $25,000 | $500 | $12,000 | $12,500 | $15,000 |
| above $25,000 | $1,000 | $29,000 | $30,000 | $36,000 |

Increment bands are the conventional ladder used across the major platforms; the premium applied in the last column is
the 20% starting value recorded on 2026-09-11. Houses publish their own ladders in the conditions of sale and a
few differ, particularly at the top end.

## Why the winning bid is the underbidder's maximum plus one step

A maximum bid is an instruction to a machine, not an offer to pay that amount. You tell the platform the most you are
willing to go to, and it bids on your behalf in the fixed steps above — one step at a time, only as far as it has to.
If nobody pushes you, your maximum is never reached and never revealed.

So the price is set by the second-highest bidder, not by you. Read the third and fourth columns of the table above: an
underbidder who stopped at $290 in the $10 band hands you the lot
at $300, whatever your maximum was. This is why raising a maximum bid by a comfortable margin
often costs nothing, and why lowering it by one step can lose a card by the width of that step.

One thing to get right: leave the maximum *on* a step rather than between two. A maximum of
$295 in a $10 band behaves exactly like a maximum of
$290 against most competing bids, because the machine can only place bids on the ladder.
The extra five dollars buys nothing and occasionally causes an odd tie-break result.

## What does a $1,000 hammer actually cost the buyer?

On the values loaded above, $1,225. The auctioneer calls $1,000; the house adds a
20% premium of $200; shipping and handling adds $25.00. That is
122.5% of the number everybody in the room heard.

Add sales tax and the gap widens again. At 7% charged on hammer, premium and shipping together, the same lot costs
$1,311 — 131.1% of hammer. That is the figure to compare against a
marketplace price, and it is the one comparison most bidders never make, because the hammer price is the number that
gets quoted afterwards and remembered.

Turn the question round and it becomes a budget. With $1,500 to spend and the same premium and shipping, the
highest hammer bid that stays inside the budget is $1,229. Add 7% tax and it drops to $1,147 — a
difference of $81.78 in what you can safely bid, caused by a line that never appears on the
bidding screen.

*The same structure at five lot sizes, with $25 of shipping on every row · a 20% premium recorded
 2026-09-11*

| Hammer | Buyer pays | As % of hammer | Consignor banks at 0% | Consignor banks at 10% | Gap at 10% |
| --- | --- | --- | --- | --- | --- |
| $250 | $325 | 130% | $250 | $225 | $100 |
| $1,000 | $1,225 | 122.5% | $1,000 | $900 | $325 |
| $2,500 | $3,025 | 121% | $2,500 | $2,250 | $775 |
| $10,000 | $12,025 | 120.2% | $10,000 | $9,000 | $3,025 |
| $50,000 | $60,025 | 120% | $50,000 | $45,000 | $15,025 |

Read the third column down the table. A fixed shipping charge is
10% of the smallest lot and
0.05% of the largest, so the all-in percentage falls
towards the premium as the lot grows. Everything above the premium on a small lot is postage, which is the argument for
consolidating several lots from the same sale into one shipment.

***At a 20% premium and a 10% commission, the house keeps 30% of every hammer price, and the buyer and the consignor never see the same number.** The shaded wedge is the house's share of the lot. On a $5,000 hammer the buyer writes $6,000 and the consignor receives $4,500 — $1,500 apart on one card. The premium is the 20% starting value recorded on 2026-09-11; the commission shown here is 10% rather than the 0% default, because a wedge of zero commission would hide the consignor's side of the same structure. Shipping and tax are excluded. Free to reuse with a link to this page*

## The house is paid from both sides of the same lot

An auction house charges the buyer a premium and charges the consignor a commission, on the same object, in the same
transaction. That is the structural fact that makes auction arithmetic different from a marketplace sale, where one
party pays one fee.

On strong material the commission is frequently waived, because the premium alone pays the house and the competition
between houses is for consignments rather than for bidders. The starting value in the panel is therefore
0%, which looks generous until you notice that the buyer has already paid $200 on the
same $1,000 lot. Move the commission to 10% and the house take goes from $200 to
$300, which is 30% of hammer.

- **The premium is not negotiable** and is stated in the conditions of sale, usually in the first two clauses.
- **The commission often is negotiable**, and on good material the first question to ask a house is what it becomes at zero.
- **Fixed consignor fees are separate** — photography, cataloguing, insurance in transit — and they do not scale with the hammer, so they hurt small lots most.
- **Shipping and tax go elsewhere.** Neither is the house's money, which is why they sit outside the house-take figure in the panel above.

## What the same card has to fetch for you to get out level

A buyer pays the hammer plus the premium and a consignor receives the hammer minus the commission, so a card bought and
later sold through the same structure has to rise by the sum of both before its owner is level. The table puts numbers
on that at a 20% premium.

*How far a card has to hammer above your purchase to break even, at a 20% buyer's premium*

| Consignor commission | Multiple of your hammer | Required gain | On a $1,000 purchase |
| --- | --- | --- | --- |
| 0% | 1.200× | 20.0% | $1,200 |
| 5% | 1.263× | 26.3% | $1,263 |
| 10% | 1.333× | 33.3% | $1,333 |
| 15% | 1.412× | 41.2% | $1,412 |
| 20% | 1.500× | 50.0% | $1,500 |

Premium and commission applied to the hammer price only; shipping, tax and any grading spent in between are additional.
The highlighted row is the 0% commission this page starts from, recorded on 2026-09-11.

Read the bottom row before the top one. A card bought at a 20% premium and later consigned at a 20% commission has to
hammer 50% higher than you paid before you see your own money again. That is not
an argument against auctions, which are the right venue for material whose price is genuinely unknown. It is an argument
against treating the hammer price as the cost of ownership, and it is the same arithmetic the
[ROI calculator](https://sportscardradar.com/tools/card-roi-calculator/) applies to a holding period.

## Before you bid, in this order

1. **Find the premium in the conditions of sale.** It is a percentage and it is stated plainly. Type it into the field above and stop using the default, which is a starting value rather than a rate.
2. **Find the shipping policy.** Some houses quote it, some invoice it afterwards, and on a slabbed card it is rarely trivial. A number you have to guess belongs in the field as your worst case.
3. **Decide whether tax applies, and to what.** Tick or untick the box above. On the worked lot it is the difference between $1,225 and $1,311.
4. **Set your all-in budget, then read the maximum hammer bid.** That number, not your budget, is what goes into the bid box. Rounding it up to the next increment is how a budget quietly fails.
5. **Check the comp before you commit.** An auction result is not a comp until it is one of several. Work the market price out from sold prices with the [card value calculator](https://sportscardradar.com/tools/card-value-calculator/) and compare it with your all-in total, not with the hammer.
6. **Leave the maximum and walk away.** The machine bids for you in fixed steps and will not go above the number you set. Watching it live is how the number changes.

***The premium, the shipping and the tax come out of the budget before the bid does, so the number that goes in the bid box is always below the number in your head.** At a 20% premium with $25 of shipping, a $1,500 budget allows a hammer bid of $1,229; add 7% tax and it falls to $1,147. The gap widens with the budget: at $5,000 the same two settings allow $4,146 and $3,873. Computed with the same function the calculator runs, at the starting values recorded on 2026-09-11. Free to reuse with a link to this page*

## The consignor's side of the same lot

Consigning is the mirror image, and the arithmetic is simpler because there is only one deduction: the commission, plus
any fixed fees the house charges for photography, cataloguing and insurance in transit. On the lot loaded above at the
0% starting commission, the consignor banks $1,000 from a $1,000 hammer, which is the
whole of it.

What that simplicity hides is the timing and the uncertainty. An auction house takes weeks to catalogue, weeks to run
the sale and weeks to settle, so the money arrives long after the card leaves — which is why the
[route comparison](https://sportscardradar.com/tools/where-to-sell-calculator/) gives the auction house the longest days-to-cash figure
of the seven routes it prices. And the hammer is not known in advance. A reserve protects the downside; nothing
guarantees the upside.

The practical question for a consignor is therefore not the commission but whether the bidder pool is the thing that
sets the price on this particular card. On material with a deep comp history, it is not: the price is already known and
a direct sale reaches it faster and more cheaply. On material where two determined bidders could double the result,
the auction is the only venue that finds out.

## Bottom line

A hammer price is neither what the buyer pays nor what the consignor receives. The buyer adds a premium — the calculator
starts at 20%, recorded on 2026-09-11 — plus shipping and, in most jurisdictions, sales tax charged on the
premium as well as the hammer. The consignor subtracts a commission, which is frequently zero on material a house wants
because the premium alone pays it. On a $1,000 hammer with $25.00 of shipping and no tax, the buyer pays
$1,225 and the consignor banks $1,000. A maximum bid is not the price you pay: the
platform bids for you in fixed steps, so the winning price is the underbidder's maximum plus one increment. And because
the house is paid on both sides of a round trip, a card bought at a 20% premium must hammer
20% higher at a zero commission, or
33.3% higher at a 10% commission, before its owner is level. Read the
conditions of sale for the real figures and type them in; nothing on this page is a rate.

## Questions this tool gets asked

What is a buyer's premium on a card auction?

A percentage added to the hammer price and paid by the winning bidder on top of it. The calculator starts at 20%, which a buyer’s premium of about a fifth of the hammer price is the common shape across the major card auction houses, and the consignor commission on good material is frequently zero because the premium already pays the house. On the $1,000 lot loaded above that is $200, so the winning bidder writes a cheque for $1,225 including shipping while the auctioneer announced $1,000. The premium is stated in the terms of the sale you are bidding in, and it is the single number to find before your first bid.

Does a maximum bid mean I pay my maximum?

No, and that is the point of leaving one. The platform bids on your behalf in fixed increments, so you pay one increment above the underbidder's maximum rather than your own. At a $500 level the step is $10, so an underbidder who stopped at $290 sets your price at $300 even if your maximum was $450. The exception is when two maximums are within one increment of each other, in which case the earlier bid wins at the lower price.

Is sales tax charged on the premium too?

Usually yes, and the calculator has a checkbox for it because the treatment varies by jurisdiction and by house. It is not a small line. On the $1,000 lot above, 7% tax charged on hammer, premium and shipping together comes to $85.75, and the all-in total moves from $1,225 to $1,311. Work it out before bidding rather than at checkout, because it is the difference between staying inside a budget and going over it.

Why is the consignor commission often zero?

Because the buyer's premium has already paid the house. On material an auction house wants, the commission is frequently waived and occasionally negative — a cash advance or a share of the premium back to the consignor — because the competition between houses is for consignments rather than for bidders. On ordinary material the commission reappears. Both the premium and the commission are editable here, and 2026-09-11 is the date the starting values were recorded.

How much does a card have to appreciate for me to break even at auction?

More than most bidders assume, because the house is paid on both sides of the round trip. At a 20% premium and a zero consignor commission, a card has to hammer 20% higher than you bought it for before you are level. Put a 10% consignor commission on the sale side and the figure becomes 33.3%. That is before shipping in either direction and before any grading you paid for in between.

What is the house take on a single lot?

The premium plus the commission plus any fixed consignor fees, all measured against the hammer price. On the lot loaded above at a 0% commission it is $200, or 20% of hammer, all of it from the buyer. Change the commission to 10% and it becomes $300, or 30%, split across both parties. Neither figure includes the shipping and tax the buyer pays, which go to a carrier and a revenue department rather than to the house.

Should I set a maximum bid or bid live at the end?

A maximum bid left early is the disciplined option, because it commits you to a number chosen while you were calm and it costs nothing when nobody pushes it. Bidding live at the end is where budgets fail, since each increment feels small against a total you have stopped recalculating. Whichever you choose, work out the all-in figure first: the number that matters is the premium, the shipping and the tax added to the bid, and this calculator prints the highest hammer bid a given budget allows.

Are the defaults in this calculator the real rates?

They are starting values with a date on them, not the rates for any particular sale. A buyer’s premium of about a fifth of the hammer price is the common shape across the major card auction houses, and the consignor commission on good material is frequently zero because the premium already pays the house. Both are editable, and both are stated in the terms of the sale you are bidding in — read them rather than trusting a default. The house you are bidding in publishes both figures in its conditions of sale, usually in the first two clauses, and they differ between houses and sometimes between sale formats at the same house.

## What people open next

1. [**Where to sell sports cards: seven routes compared net of every fee** Seven routes to cash, ranked by what actually lands and how long it takes.](https://sportscardradar.com/tools/where-to-sell-calculator/)
2. [**eBay fee calculator for trading cards: what you keep after every fee** Every fee as an editable field, the take-home percentage, and your break-even price.](https://sportscardradar.com/tools/ebay-fee-calculator/)
3. [**Card break-even calculator: the price a card has to fetch to get even** Solve for the sale price that returns exactly what the card has cost you.](https://sportscardradar.com/tools/break-even-calculator/)
4. [**Sports card inflation calculator: what an old card price is worth now** What a 1989 price is in today’s money — and whether the card actually gained anything.](https://sportscardradar.com/tools/inflation-calculator/)
5. [**Sports card shipping calculator: PWE, tracked or insured, by card value** The exact card value at which a plain envelope stops being the cheap option.](https://sportscardradar.com/tools/shipping-calculator/)
6. [**Sports card ROI calculator: total return, annualised, after fees** Total return and CAGR, net of the selling fee people forget to subtract.](https://sportscardradar.com/tools/card-roi-calculator/)

All 24 calculators are listed on the [free tools page](https://sportscardradar.com/tools/),
and the longer write-ups live in [scouting](https://sportscardradar.com/scouting/).

## The card is in your hand. Point the camera at it.

These calculators work on numbers you already have. Valdar gets you the numbers: it identifies the card from one
photo, pulls what that exact card has actually sold for, and estimates the four grading sub-dimensions before you
pay a submission fee. Free to try on iPhone and Android.

[Download on theApp Store](https://apps.apple.com/app/apple-store/id6757157972?pt=127157325&ct=seo&mt=8) [Get it onGoogle Play](https://play.google.com/store/apps/details?id=com.vastflow.sportscard.app&referrer=utm_source%3Dsportscardradar%26utm_medium%3Dweb%26utm_campaign%3Dseo)

---

HTML version: https://sportscardradar.com/tools/auction-calculator/
Structured data for this site: https://sportscardradar.com/api/v1/openapi.json · https://sportscardradar.com/llms.txt
Free to quote and reuse with a link back to the source URL above (CC BY 4.0).