Too many or too few?

Order too much and your cash sits in stock you end up discounting. Order too little and you give up sales you could have made. Both are expensive, and they are rarely expensive by the same amount. Put one product in and see which mistake actually costs you more.

What you normally sell one for.

$

What one unit costs you by the time it's ready to sell. Product cost plus freight and duty.

$

Costs that stay roughly the same regardless of selling price, such as fulfilment, pick-and-pack, or outbound shipping.

$

Costs that change with the selling price, such as marketplace, payment processing, or percentage-based platform fees.

%

The same number is used both ways. Whole units only.

#

The additional storage, aging or warehouse cost you expect before that excess unit eventually sells or is disposed of.

$

Set the discount you realistically think you'd need to clear the excess.

30% off = $35.00/unit

The rest is assumed to be written off or disposed of. Be conservative.

100 units cleared · 0 units written off

At about 97.9% off, or $1.06/unit, the two mistakes have the same estimated financial impact. Sell below $1.06/unit, or discount by more than 97.9%, and carrying too many becomes the bigger financial hit.

100 too many

+$790

estimated contribution after clearance

100 too few

−$2,400

contribution lost

Running out has the bigger financial hit

about $3,190 bigger than the excess-inventory outcome

based on a 30% discount and 100% expected clearance sell-through

Under these assumptions, running out has the higher estimated financial impact. Every sale you miss gives up $24.00 of contribution, while the excess units still come out contribution-positive after clearance.

This compares how expensive each mistake is, not how likely each mistake is to happen.

If you carry 100 extra units

Per unitTotal
Cash invested in excess inventoryshown separately from the estimated financial impact$18.00$1,800
Expected to clear, and to write off100% of 100 units100 cleared0 written off
Clearance revenue30% off your $50.00 price, on 100 units$35.00$3,500
Landed coston the cleared units−$18.00−$1,800
Fixed selling and fulfilment costs−$5.00−$500
Selling fees at 6%on the clearance price−$2.10−$210
Extra holding costs−$2.00−$200
Contribution from the 100 cleared units+$7.90+$790
Total estimated financial effect+$7.90+$790

If you miss 100 sales

Per unitTotal
Revenue not capturedshown separately from the estimated financial impact$50.00$5,000
Contribution per sale$50.00 price − $18.00 landed − $5.00 fixed selling − $3.00 fees at 6%$24.00$2,400
Contribution lost−$24.00−$2,400

What this does, and what it won't

It compares cost, not likelihood. The two mistakes are priced at the numbers you enter. How likely each one is to happen is a demand question, and this tool doesn't answer demand questions.

It treats the two sides differently, on purpose. A missed sale gives up its full contribution. Excess units aren't charged for a full-price sale that was never going to happen, so they're measured on what they actually cost you after clearance. That asymmetry is the whole point, and it's why excess stock can still come out contribution-positive at a shallow discount.

It shows you the price that flips the answer. You'll get the clearance price and discount at which the two mistakes cost exactly the same, so you can see how much of the answer rests on your discount assumption rather than on the product itself.

It separates clearing from writing off. Not all excess clears. You set the share you expect to sell at the clearance price, and the rest is written off at its landed cost plus holding cost, with no selling fees, because those units never ship.

It will not tell you how much to order. This is not a reorder quantity, a safety stock level or a forecast. It knows nothing about your lead times, your demand, or how much cash you have available.

One product at a time. One SKU, one quantity, two mistakes, one comparison.

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