Amazon FBA Startup Cost Calculator

The cash a launch actually needs: the first purchase order, the second order that comes due before the first has sold out, and the gap between them. A profitable unit and an affordable product are different tests. 100% free with no signup and no API - your supplier costs and forecasts are calculated in your browser and never leave your device.

Where the money goes, and when

1. Before launchPay for the first order and the launch costs
2. Day 0
3. Reorder point reached - pay for the second order
4. Second order arrives, stock is replenished

How the cash gap works

A per-unit profit calculation answers one question: does this product make money on each sale. It says nothing about whether you can afford to keep selling it. Those come apart because of timing.

You order before you run out, not after. The reorder point is the stock level at which the next order has to be placed for it to land before the shelf is empty:

reorder point = units per day × (replenishment lead time + safety buffer)

Replenishment is the whole chain - production, shipping and customs, Amazon receiving - and it is usually the part new sellers underestimate. With a 60-day chain and a 14-day buffer at 10 units a day, the next order goes in while 740 units are still sitting in the warehouse. Out of a 1,200-unit first order, that is day 46.

Now the second problem. Amazon does not pay you when the customer pays. Sales from the last two weeks before the reorder date have not settled yet, so they cannot fund the supplier invoice:

paid units = units per day × max(0, days to second order − payout delay)

And what those sales return is not profit:

cash returned per paid sale = retail price − operational cost per unit

That figure includes recovery of the unit's own landed cost, which is exactly why it can pay for a reorder. It is a larger number than profit and it means something different. Whatever the second order costs beyond it is the shortfall:

shortfall = max(0, second-order cost − cash returned)

starting cash = first order + launch costs + shortfall

Order quantities: why the second order is smaller

Both quantities are sized to the same target - enough stock to outlast the lead time and still leave your chosen days of cover once the replenishment lands - and then floored at your MOQ. The difference is what is already on the shelf. At launch that is zero. At the reorder point it is a full reorder point's worth of stock, and that counts against the order:

first order = units per day × (lead time + days of cover)

second order = units per day × (days of cover − safety buffer)

Both then take the MOQ floor. When MOQ binds it usually binds on the second order first, which is worth knowing: a supplier minimum that looked reasonable against your launch quantity can force a much larger reorder than the forecast needs.

What this first version simplifies

• Landed cost is treated as one outflow at order time. Deposit-and-balance payment schedules are not modeled, so a 30/70 supplier split will shift the timing.
• The operational cost carried over from the profit calculator includes cost of capital, which is not a real cash outflow. Cash returned is slightly conservative.
• Amazon settles on a payment cycle, not per sale. The payout delay is modeled as a flat lag on every unit.
• Sales run at a constant daily rate from day 0. There is no launch ramp, no seasonality, and no honeymoon period.
• The model stops at the second order. Cash exposure past the second replenishment is not projected.
• One product, one supplier, one currency. No VAT settlement timing, no purchase-order financing interest, no split shipments.

The output is a planning estimate, not a forecast. Treat the sales figure as the assumption it is - the stress line under the results shows how much the answer moves when it is wrong.

FBA startup cost questions

How much money do you need to start Amazon FBA?

More than the first purchase order, which is the number most new sellers budget for. You also need one-time launch costs and enough left over to pay for the second order, which comes due long before the first order has sold out. Enter your own figures above for the number that applies to you.

Why is the second order due so soon after launch?

Because you have to order before you run out, not after. The reorder point is your daily sales multiplied by the replenishment lead time plus your safety buffer, and replenishment is the whole chain: production, shipping and customs, and Amazon receiving. If that chain takes 60 days and you want 14 days of safety stock, you place the next order while stock is still on the shelf.

Is cash returned from sales the same as profit?

No, and confusing the two is what makes a working-capital gap invisible. Cash returned per sale is the retail price minus what Amazon and advertising take, so it includes recovery of the unit's own landed cost as well as its profit. That is why it can fund a reorder. Profit is what is left after the landed cost is subtracted too.

Can selling faster than forecast make the cash problem worse?

Yes, and this is the trap. Your first order is already placed at the quantity you forecast. Selling faster does not make it bigger, it makes it run down sooner, so the reorder point arrives earlier. Arrive there before Amazon's payout delay has cleared any sales and none of that revenue is available to pay the supplier.

Do my supplier costs and sales forecasts stay private?

Yes. Your MOQ, landed cost, and forecast are competitive information, so this calculator is built not to have them: no account, no API, no server storing your figures. The math runs client-side in your browser. Values carried over from the profit calculator travel in the URL fragment after the # sign, which browsers never send to a server. See the privacy policy.