Free FBA tool
PPC Throttle Calculator
Your numbers
Ad-attributed units / total units, same 30 days. Example: 200 / 500 = 40%.
Days from arrival to sellable.
Arrives in 55 days, sellable in 60.
+ - How to find these numbers in Seller Central
- Units sold: Business Reports, Detail Page Sales and Traffic by Child Item, set to the last 30 days. Use a normal window: a lightning deal or a month you were already throttling will skew the result, so adjust toward a typical month.
- Units on hand: Manage FBA Inventory, the available (sellable) quantity. Do not count units still inbound.
- PPC share: take ad-attributed units for the SKU from the Advertising console over the same 30 days, and divide by the total units above. It takes a couple of minutes per SKU.
- Restock date: your PO or freight forwarder ETA. If part of the order arrives early by air, run this once for the partial, then again from that date with the combined stock.
Cut PPC-driven sales by
50.0%
You have 48.0 days of cover but need 60.0. Slow from 16.67 to 13.33 units a day: organic keeps selling 10/day, so ad-attributed sales drop from 6.67 to 3.33/day.
This is a sales target, not a budget cut. Ad spend does not move ad sales one for one. Start by capping daily budgets on your highest-spend campaigns and trimming bids on the keywords driving the most ad-attributed units, then check in a few days whether ad sales are near 3.33/day and adjust again.
Days of cover today
48.0 days
At the current pace
Stock must last
60.0 days
Arrives day 55, sellable day 60
Sustainable pace
13.33/day
Sell no more than this
PPC-driven sales now
6.67/day
40% of 16.67/day
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Inventory Hero
This check, run every morning across your whole catalog
This page checks one SKU from numbers you type in. Inventory Hero tracks days of cover on every SKU automatically from your live sales and inbound shipments, so the moment a fast mover's cover falls short of its restock date, you know which campaigns to ease off, before the stockout is already scheduled.
- Live days of cover per SKU, updated from your sales feed
- Restock dates from your actual POs and inbound shipments
- Catch the SKUs that need a throttle before they run dry
No credit card required.
How the throttle math works
PPC throttle
Sustainable pace = units on hand / days until restock (+ buffer)
PPC cut % = (current pace - sustainable pace) / PPC-driven pace
Your 30-day sales set the current daily pace, and your PPC share splits it into organic and ad-driven units. Organic sales cannot be throttled, so the entire slowdown has to come out of the ad-driven share. If the required cut is more than 100% of your ad sales, no throttle can save the listing, and the calculator says so instead of pretending otherwise.
Worked example
You sold 500 units in the last 30 days, 40% of them ad-attributed. You have 800 units on hand, and the next shipment arrives in 55 days, plus a 5-day receiving buffer, so your stock has to last 60 days.
- Current pace: 500 / 30 = 16.67 units a day (6.67 ad-driven, 10 organic)
- Days of cover: 800 / 16.67 = 48 days, against 60 days to bridge
- Sustainable pace: 800 / 60 = 13.33 units a day
- Total slowdown: (16.67 - 13.33) / 16.67 = a 20% cut to overall sales
- PPC throttle: all 3.33 of those units come out of the 6.67 ad-driven units, so cut PPC-driven sales by 50%
Organic keeps selling 10 a day, ads ease from 6.67 down to 3.33, and the stock lasts exactly until the restock is checked in, at full price the whole way. Remember that this is a target sales rate rather than a budget instruction: cut budgets and bids toward it, then re-measure. When the new shipment lands, size the next order with the restock calculator and set the trigger level with the reorder point calculator so the next gap never opens. For the strategy behind the numbers, read PPC x Inventory: don't advertise what you can't restock.
Key terms
- Days of supply (days of cover)
- How long your on-hand stock lasts at the current sales pace: units on hand divided by daily velocity. The throttle compares it to the days you need to bridge.
- Sales velocity
- Average units sold per day. Here it is the 30-day average, split into an organic share and an ad-driven share you can throttle.
- Receiving buffer
- Days between a shipment reaching Amazon and its units becoming sellable. Your stock has to bridge to the sellable date, not the arrival date.
- PPC share of sales
- Ad-attributed units divided by total units for the SKU. Related to TACoS but measured on sales, not spend, because the throttle acts on your sales rate.
Frequently asked questions
Should I pause PPC or throttle it when stock gets tight?
Throttle first. Pausing is a blunt switch: you lose campaign momentum, ad history, and placements you paid to win, and restarting costs more than easing off did. Throttling cuts ad-driven sales just enough that your stock bridges to the restock date while the campaigns stay warm. The one time a full pause is right is when even cutting PPC to zero cannot stretch your stock far enough, which this calculator calls out explicitly as an unavoidable stockout. At that point pause the ads and work the other levers: raise price, pull the restock forward, or air-freight a partial shipment.
Will throttling my ads hurt my organic rank?
Some, but far less than the alternative. Reduced ad traffic can soften the sales velocity that feeds organic rank, so expect a gradual, recoverable drift rather than a cliff. This calculator deliberately assumes organic sales are unaffected by the ad cut, which is the optimistic case, so treat the computed cut as a floor and watch your organic sales for a halo effect. A stockout, by contrast, zeroes your velocity outright, and that is the outcome the throttle exists to prevent.
What happens to my rank when I go out of stock?
Your sales velocity drops to zero, and velocity is the main input to organic rank. The listing slides down search results, your ad campaigns stop serving and lose momentum, and competitors absorb your demand and reviews while you are dark. When you restock, you typically have to spend on PPC again to buy back the rank you previously earned, so the stockout costs you twice: the lost sales during the gap and the relaunch spend after it. Slowing to full-price sell-through almost always beats paying to accelerate your own stockout.
How do I actually cut PPC-driven sales by a target percent?
Ad spend does not map linearly to ad sales, so treat the output as a sales-rate target rather than a budget formula, which is why the result states the units-per-day figure to steer toward. A practical starting move for a 50% sales cut: cap daily budgets at about half of current spend on your highest-spend campaigns and trim bids 15 to 25% on the keywords driving the most ad-attributed units, then re-measure after a few days. If ad-driven sales are still above the target pace, cut further; if they fell too far, ease back. Repeat weekly until the restock lands. The point is to steer to the sustainable units-per-day figure, not to hit an exact spend number.
What is my PPC share of sales and where do I find it?
It is the percent of a SKU's total sales that are attributed to ads. Take ad-attributed units (or sales) for the SKU from the Advertising console over the last 30 days, and divide by total units from Business Reports for the same window. If you sold 500 units and 200 were ad-attributed, your PPC share is 40%. It is related to TACoS, which divides ad spend by total sales; this ratio divides ad-driven sales by total sales, because the throttle acts on sales, not spend.
Why does the calculator add a receiving buffer after the arrival date?
Because arrival is not sell-through. A shipment that reaches Amazon still has to be received and checked in before those units can sell, and that gap is commonly a few days and longer in Q4. If you plan your stock to last only to the truck date, you can go out of stock while your own inventory sits in the building. The calculator therefore stretches your stock to the arrival date plus the buffer, and shows both milestones separately so you can see which one your cover actually has to reach.
Inventory Hero
Run the throttle check before it's urgent
Inventory Hero watches days of cover against real restock dates on every SKU, so you see which products need their ads eased off weeks before the stockout, and which can keep pushing at full budget.
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<iframe src="https://www.inventoryhero.ai/embed/ppc-throttle-calculator?utm_source=embed&utm_medium=iframe" title="PPC Throttle Calculator by Inventory Hero" width="100%" height="720" style="border:1px solid #e5e5e5;border-radius:16px;max-width:680px" loading="lazy"></iframe>
<p style="font:13px/1.5 system-ui,sans-serif;text-align:center;margin:8px 0 0"><a href="https://www.inventoryhero.ai/tools/ppc-throttle-calculator">PPC Throttle Calculator</a> by Inventory Hero</p>See all our free Amazon FBA calculators.