At a glance
The share of your Amazon revenue that Amazon keeps in fees. It divides total Amazon fees (referral plus FBA fulfilment plus storage) by ordered product sales, giving one ratio that tells you how much of every pound of revenue is gone before cost of goods. It is the single most useful FBA-economics number because it normalises away volume: rising sales hide rising fees, but this ratio does not. When it creeps up, your mix has shifted toward higher-fee products, a fee schedule changed, or storage on slow stock is mounting.
| What it counts | total Amazon fees / ordered product sales, expressed as a percentage. Total fees blend referral fees, FBA fulfilment fees, and storage fees over the same window. |
| Why a ratio | Absolute fees grow with sales, so they never alert usefully. The ratio strips out volume and exposes whether fees are growing faster than revenue, which is the thing that actually erodes margin. |
| What “good” looks like | There is no universal number; it depends on your category mix and price points. The discipline is watching your own baseline. A ratio that drifts up period over period is the warning, wherever it starts. |
| What pushes it up | A shift toward cheaper or bulkier items (higher FBA fee share), a move into higher-referral-fee categories, growing storage fees on slow-moving stock, and Amazon fee-schedule increases or peak surcharges. |
| What this does NOT include | Advertising cost (ACOS / TACOS), cost of goods, and refunds are not in this ratio. It is Amazon’s platform fees only. For the after-everything view, see Net Revenue (after fees + refunds). |
| FBA vs FBM | For FBA sellers the ratio captures fulfilment fees; for FBM sellers the fulfilment component is your own shipping cost (not an Amazon fee), so the ratio is dominated by referral fees. |
| Reading the gauge | Lower is better. Compare to the prior period: a rising ratio is the signal, even if the absolute level looks acceptable. |
| Currency / unit | percent |
| Time window | 30D vsP (last 30 days vs the prior 30 days) |
| Alert trigger | >35% |
| Roles | owner, finance |
Calculation
Calculated automatically from your Amazon Seller Central data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.Worked example
A health-and-beauty brand on Amazon UK, FBA, 30-day window ending 01 May 26 vs the prior 30 days. All numbers illustrative.| Component | Prior 30D | This 30D |
|---|---|---|
| Ordered product sales | £180,000 | £176,000 |
| Referral fees | £25,200 (14%) | £25,500 (14.5%) |
| FBA fulfilment fees | £27,000 (15%) | £29,000 (16.5%) |
| Storage fees | £3,600 (2%) | £6,300 (3.6%) |
| Total fees | £55,800 | £60,800 |
| Fees % of Revenue | 31.0% | 34.5% |
- Revenue fell but fees rose, so the ratio jumped 3.5 points. Sales dipped slightly while total fees climbed. That is the worst combination for the ratio and exactly why it is more informative than the absolute fee total, which barely moved.
- Storage fees nearly doubled and drove most of the increase. Storage went from 2% to 3.6% of revenue. That points at slow-moving stock ageing in the fulfilment centre. The fix is inventory action (markdown, removal), not a packaging or pricing change. Check FBA Storage Fees and ASINs Approaching Long-Term Storage.
- 34.5% is approaching the alert line. It is just under the
>35%threshold. One more point, from another storage cycle or a mix shift, tips it over. This is the moment to act, before the alert, not after. - The ratio excludes advertising and cost of goods. A 34.5% fee ratio is not your total cost; add ACOS / TACOS and cost of goods to understand true profitability. This card isolates the Amazon-platform slice on purpose.
- Decompose before you act. The ratio rose, but the action depends on which component drove it. Referral was flat, fulfilment rose a little (mix or a fee change), storage spiked (slow stock). Always break the ratio into its three parts before deciding what to fix.
Sibling cards merchants should reference together
The ratio is the headline; these are its components and consequences:| Card | Why pair it with Fees % of Revenue |
|---|---|
| FBA Fees | The fulfilment-fee component. A rising ratio driven by fulfilment points here. |
| Referral Fees | The percentage-of-sale component; a category mix shift moves this. |
| FBA Storage Fees | The storage component; slow stock is the usual cause of a creeping ratio. |
| Per-ASIN Fee Outliers | The ASINs dragging the ratio up; the targeted worklist. |
| Net Revenue (after fees + refunds) | The after-fees bottom line this ratio feeds into. |
| Total Revenue | The denominator; the ratio reframes revenue net of platform cost. |
Reconciling against Amazon Seller Central
Where to look in Amazon Seller Central:Seller Central → Reports → Payments → Date Range Reports (Summary). This breaks the period into ordered product sales, referral fees, FBA fees, and storage fees. Dividing total fees by product sales reproduces this card.The Payments → Transaction view gives the order-level detail behind each fee line. Timing, settlement, and reporting-lag table:
| Topic | Detail |
|---|---|
| Timezone | Payments reports use your marketplace account timezone; Vortex IQ aligns to your configured reporting timezone. The ratio is robust to boundary effects over 30D. |
| Accrual vs settlement | Referral and fulfilment fees accrue with the order; storage fees are charged monthly. A storage charge landing inside the window lifts the ratio for that period even though it covers stock held earlier. |
| Storage-fee lumpiness | Monthly storage fees and periodic long-term storage fees arrive in lumps, so the ratio can step up in the month they hit. Read the trend across several periods, not one. |
| Fee schedule / surcharge changes | Amazon revises fees periodically and adds peak surcharges; a ratio rise can reflect a rate change rather than your own mix. |
| Reason | Direction | Why |
|---|---|---|
| Fee components included | Either | Whether storage is in the numerator, and how refund-related reversals are treated, changes the ratio. The card follows its configured definition. |
| Accrual vs settlement window | Either | The card aligns fees to the order / charge date; a settlement-bucketed report differs near a period edge. |
| Sales denominator basis | Either | Using ordered product sales vs shipped sales as the denominator shifts the ratio. |
| Storage timing | Temporary | A monthly storage charge inside the window can spike the ratio relative to a report that spreads it. |
| Card | Expected relationship | What causes legitimate divergence |
|---|---|---|
ebay.fees-of-revenue | Marketplace peer. Same ratio concept; eBay’s fee mix is dominated by the final-value fee, Amazon’s by referral plus FBA plus storage. Independent populations. | Different fee structures mean the levels are not directly comparable; use as a peer benchmark. |
shopify.total_revenue | Independent channel. DTC has its own cost stack (payment processing, fulfilment), not Amazon fees. | No reconciliation; compute a DTC equivalent ratio separately for a fair channel comparison. |
Known limitations / merchant FAQs
Is 35% a lot? It depends entirely on your category and price points. Some categories carry a 30% blended fee load as normal; others run lower. The>35% alert is a sensible default, but the real signal is your ratio drifting up from its own baseline, not the absolute level.
My fees barely changed but the ratio jumped. How?
The ratio has a denominator. If revenue fell while fees held flat (or rose slightly), the ratio climbs. That is the point of using a ratio rather than an absolute, it catches margin erosion that the fee total hides.
Does this include my advertising spend?
No. This ratio is Amazon platform fees only (referral, fulfilment, storage). Advertising cost is tracked separately via ACOS / TACOS, and cost of goods is not on Amazon’s side at all. For the after-everything figure, use Net Revenue (after fees + refunds).
Why did the ratio step up in one specific month?
Most often a monthly or long-term storage fee landed inside that window. Storage fees arrive in lumps, so the ratio can jump in the month they hit even though the underlying stock was held earlier. Read the trend across several periods.
Can I change the alert threshold?
Yes. The >35% default is configurable per profile in the Sensitivity tab. Set it just above your normal baseline so the alert fires on genuine drift rather than on your steady-state fee load.