Estimate US FBA referral, fulfillment, monthly storage, optional aged-inventory surcharge, removal/disposal, labeling, and prep — then compare to FBM with your own ship cost. All processing runs in your browser. Free tools hub.
Surcharge-style estimate applies from 271+ days (illustrative).
About this tool
Selling on Amazon with Fulfilled by Amazon means every SKU carries a stack of variable costs that do not show up on a simple “price minus COGS” napkin. Referral fees depend on category. Fulfillment fees depend on size tier and the greater of unit weight or dimensional weight. Storage bills your inventory by cubic foot, with higher rates in peak months. Slow movers can trigger aged-inventory surcharges. Optional services—labeling, prep, removal, disposal—add line items that matter when you model hundreds of units. Private-label sellers, retail arbitrage operators, and agencies advising brands all need the same thing: a transparent bridge between listing price, Amazon’s take, and true contribution profit.
This free SynthQuery Amazon FBA Fee Calculator runs entirely in your browser. Enter your selling price, packaged length, width, and height in inches, item weight in pounds, and a category preset that maps to an illustrative referral percentage (including common eight-to-fifteen percent bands and category-specific floors where applicable). The tool sorts your dimensions to longest, median, and shortest sides, computes dimensional weight using the standard US divisor of one hundred thirty-nine cubic inches per pound, and takes billable shipping weight as the maximum of actual and dimensional weight. It classifies the package into Small Standard, Large Standard, Small Oversize, Large Oversize, or Special Oversize using simplified Fulfillment by Amazon size rules, then applies non-apparel-style fulfillment fee tables. Monthly storage multiplies cubic feet by either off-peak (February through September in this model at fifty-six cents per cubic foot) or peak (October through January at eighty-seven cents). If you indicate inventory age beyond two hundred seventy-one days, an illustrative aged-inventory monthly surcharge line appears so you can stress-test slow-turn SKUs. Checkboxes and fields cover FBA label service, prep per unit, and optional removal or disposal estimates. A product cost field turns net proceeds into profit and ROI on COGS, while a parallel FBM lane compares the same price and referral stack against your own shipping and handling estimate so you can see when in-house fulfillment might win on margin—even before you factor warehouse labor.
No uploads are required; arithmetic stays on your device, which helps when supplier quotes and MAP discussions are sensitive. Use the Copy results action after a calculation to paste a concise memo into email or Notion, and follow internal links to the Free tools hub at /free-tools, the Stripe and Shopify fee calculators for adjacent payment economics, and SynthQuery’s AI Detector and Humanizer when you are polishing listing copy or compliance text. Always reconcile outputs with Seller Central’s Revenue Calculator and the official fee schedule before you commit purchase orders—marketplace fees change with policy cycles, peak storage windows, and program enrollments.
What this tool does
The calculator is organized for fast what-if reviews during sourcing calls and listing audits. Inputs are grouped logically: commercial fields first (price, category, COGS), cube and weight next, then marketplace options (storage season, age, optional services). Validation messages call out empty fields, non-numeric characters, and negative numbers where only zero-or-positive values make sense. A pending state on the Calculate action gives lightweight feedback on slower devices even though the math itself is synchronous.
Size tier detection is the technical centerpiece. After sorting dimensions, the tool applies large-standard dimensional gates (eighteen by fourteen by eight inches maximum longest, median, and shortest sides, with twenty-pound billable weight cap) and small-standard gates for thin, light parcels (fifteen by twelve by three-quarters inches with one-pound billable weight cap). Packages that exceed large standard move into oversize ladders bounded by length, girth, and weight caps, culminating in special oversize for the largest or heaviest units. Fulfillment fees read from tier-specific tables for standard sizes and formula-style increments for oversize, aligned with commonly published US non-apparel snapshots.
Referral fees multiply your price by the category rate and respect illustrative minimums where those floors matter. Monthly storage multiplies cubic feet by the season rate you select. Aged-inventory logic is deliberately conservative and educational: beyond two hundred seventy-one days, a blended surcharge line reminds you that slow turn can dominate margin on bulky items. Labeling applies a flat per-unit estimate when enabled; prep uses your typed dollars; removal uses weight-tier estimates differentiated between return and dispose paths.
The profit panel expresses price minus all enabled Amazon-side fees, then subtracts COGS for contribution dollars. ROI divides that profit by COGS, returning an em dash when COGS is zero to avoid divide-by-zero confusion. The FBM column keeps the same referral model—Amazon still charges referral on most professional seller listings—while swapping FBA fulfillment and FBA storage for your entered ship-and-handling estimate, producing an apples-to-apples channel margin snapshot excluding your warehouse time.
Accessibility is built in: labels are tied to inputs with htmlFor, error text is exposed through role alert, results publish to a polite live region, and the article/aside structure separates primary workflow from disclaimer content. Related calculators appear in a nav list for keyboard users who want adjacent tools without scrolling back to the hero.
Technical details
Referral fees on Amazon are generally a percentage of the item price for the category, sometimes subject to minimums per unit. This tool uses illustrative rates aligned with common US professional seller experiences; managed categories, fee promotions, and tax-inclusive jurisdictions can diverge. Always verify the exact rate table attached to your listing category in Seller Central.
Fulfillment fees for FBA depend on the outbound shipping weight tier within a size class. Shipping weight is the greater of unit weight and dimensional weight for many non-apparel items. Dimensional weight equals item volume in cubic inches divided by one hundred thirty-nine (inches per pound) in the US context modeled here. Cubic feet for storage equals length times width times height divided by one thousand seven hundred twenty-eight.
Size tiers group parcels by longest side, median side, shortest side, and girth (longest side plus twice the sum of the other two). Large standard items must fit within eighteen by fourteen by eight inches and twenty pounds shipping weight; small standard captures thin, light parcels with tighter dimensional caps and a one-pound shipping weight cap. Oversize ladders extend length, girth, and weight maximums until special oversize captures the remainder.
Monthly storage fees apply per cubic foot per month and historically rise during peak holiday quarters; this calculator exposes a peak window (October–January) and an off-peak window (February–September) at the illustrative rates you selected in the specification. Long-term or aged-inventory surcharges layer on when units remain in fulfillment centers beyond policy thresholds; Amazon bills the greater of volume-based and per-unit constructs in live accounts—our estimate collapses that into a single monthly warning line for planning.
Removal and disposal fees vary by size and weight; the estimates here follow common per-unit bands for returns versus disposals. Prep and labeling mirror flat service-style charges when you opt into partnered services. None of these lines include inbound placement service choices, remote fulfillment, or VAT-specific programs—extend your model when those programs apply.
Use cases
Product researchers comparing Alibaba MOQs against Amazon list prices use the calculator to see whether dimensional weight will erase margin before they order samples. If a slightly smaller mailer drops Large Standard fulfillment by a bracket, the cube field makes that discovery visible in minutes. Private-label sellers planning Q4 air freight versus ocean shifts can re-run scenarios as package density changes.
Profit analysis for wholesale suppliers entering Seller Central blends COGS from invoices with Amazon fees to quote MAP-friendly retail prices that still clear contribution targets. Agencies white-labeling dashboards for clients export Copy results snippets into weekly business review decks, then cross-link to the ROI Calculator at /roi-calculator for campaign-level returns.
FBA versus FBM decisions start with honest shipping estimates. If your FBM lane includes zone-five small parcel rates above the FBA fulfillment fee for your tier, the comparison table nudges toward FBA even before counting storage—provided you turn inventory fast enough that storage and aged fees stay small. Conversely, oversized home goods with long dock-to-dock times may show FBA storage and surcharge risk that pushes fulfillment back to merchant-fulfilled with regional carriers.
Sourcing decisions for arbitrageurs weigh clearance buy costs against predicted referral and fulfillment. When clearance SKUs are heavy or oddly shaped, billable weight spikes and the tier badge explains why a “cheap” buy cost still fails net checks. Operators bundling multipacks should re-measure the outbound ship size; bundles often jump tiers even when unit economics looked attractive singly.
Content teams drafting help articles about fees can paste neutral numbers from the tool into internal wikis, then run finished customer-facing copy through the AI Detector at /detect and Humanizer at /humanizer to keep tone compliant and human. Finance partners tie outputs to the Contribution Margin Calculator at /contribution-margin-calculator when they roll SKU-level results into operating plans.
How SynthQuery compares
Amazon’s official Revenue Calculator pulls live fee quotes tied to your seller account and SKU metadata; third-party research suites layer historical BSR and keyword demand. SynthQuery’s calculator targets a different moment: quick, transparent arithmetic you can run locally with assumptions you control, without granting API access or uploading catalogs.
Aspect
SynthQuery
Typical alternatives
SynthQuery vs Amazon Revenue Calculator
Open, assumption-driven estimates with explicit tier math, dimensional weight, and FBM comparison in one pane—ideal for supplier calls.
Tied to live SKUs and programs inside Seller Central; less handy when you only have a supplier quote and a cardboard mock-up.
SynthQuery vs Jungle Scout / Helium-style suites
Fee transparency without tying results to subscription data layers; no ASIN required.
Rich demand intelligence and profitability widgets, but often bundled into paid plans and less portable for ad-hoc cube tweaks.
Privacy posture
Runs locally in the browser; paste-sensitive COGS and dimensions without server round-trips for the arithmetic path.
Cloud suites store history and sync accounts—great for teams, heavier for quick NDA-bound sourcing chats.
When to still use Seller Central
Treat SynthQuery outputs as directional; confirm every fee line before inventory purchases.
Revenue Calculator remains authoritative for enrolled programs, promotions, and tax-inclusive marketplaces.
How to use this tool effectively
Start with the packaged dimensions you expect Amazon’s fulfillment center to measure, not the inner retail carton from the factory if the outbound ship unit is larger. Enter length, width, and height in inches using the outermost points of the sellable unit, including protective inserts if they ship with the product. Type item weight in pounds as the scale weight of that same packaged unit. If you are comparing air freight versus ocean and the sell unit differs, run separate scenarios—fee tiers react to both cube and weight.
Choose your selling price as the item price before tax but after on-page discounts only if you intend to model net customer checkout; many sellers type the headline list price and handle coupons externally. Pick the category mapping that best matches your browse node for referral fee purposes. Electronics and computing often carry lower percentage rates with minimum referral amounts; jewelry and apparel run higher. If you are between nodes, bias toward the conservative (higher) fee when planning working capital.
Set product cost or COGS to include landed cost per unit when possible: manufacturing, packaging, inbound freight to you, and duties amortized per piece. Exclude advertising here so you can read gross contribution after Amazon’s fees; move ad spend into separate MER or TACOS workflows. Enter an FBM shipping and handling estimate for a typical order—blend zones if you sell nationwide, or use your worst-case coast-to-coast label. This number powers the FBA versus FBM comparison table.
Select monthly storage season: off-peak applies the lower per-cubic-foot rate in this educational model; peak applies the higher window used for Q4 planning. Type days in FBA to surface an aged-inventory surcharge estimate after two hundred seventy-one days. Toggle FBA label service if you rely on Amazon to barcode units, add prep dollars if you use partnered prep for poly-bagging or bubble wrap, and optionally include removal or disposal with either return or destroy semantics. Click Calculate. Review size tier, billable weight, cubic footage, each fee line, total Amazon-side fees, net after those fees, profit after COGS, ROI percentage, and the FBM profit column. Iterate price, dimensions, or weight to see how dimensional weight might flip tiers when you shrink poly-mailer thickness.
After you trust a scenario, Copy results for your sourcing sheet, then Reset when you move to a different ASIN. Pair outputs with the Markup Calculator at /markup-calculator when you translate supplier quotes into list prices, and with the Discount Impact Calculator at /discount-impact-calculator before lightning deals.
Limitations and best practices
Rates change. Peak storage months, low-price FBA, remote fulfillment, dangerous goods, apparel surcharges, and inbound placement splits can all move your true statement. Reconcile this tool against Seller Central before POs, and document the date whenever you paste Copy results into a memo.
Dimensional weight sensitivity means packaging design is a profit lever. Re-run scenarios when you change inserts, swap mailers, or consolidate multipacks. Keep COGS definitions consistent—if you exclude inbound freight to Amazon here, exclude it everywhere in your cohort comparisons.
When comparing FBA to FBM, add your warehouse labor, supplies, returns processing, and customer service overhead outside this tool; the FBM lane only includes referral plus your typed shipping estimate. For marketplace payment economics beyond Amazon, bookmark the Shopify fee calculator at /shopify-fee-calculator and the Stripe fee calculator at /stripe-fee-calculator. For listing quality, pair financial outputs with SynthQuery’s AI Detector and Humanizer so customer-facing claims stay accurate and natural.
Soften templated or model-generated bullets so customer-facing copy reads natural.
Frequently asked questions
There is no single flat answer. Amazon charges a referral fee that varies by category—often around fifteen percent on many general categories but lower for some electronics and higher for jewelry or apparel in common US schedules. Fulfillment fees depend on your package’s size tier and the greater of actual weight versus dimensional weight. Storage adds a per-cubic-foot monthly charge, higher in peak months. Optional services like labeling, prep, removal, or disposal add more. This calculator estimates those components from the dimensions, weight, price, and toggles you provide; confirm the total in Seller Central for your exact SKU and programs.
The referral component is usually a percentage of item price for the category, subject to occasional per-unit minimums on low-priced electronics. Fulfillment is not a percentage—it is a tiered dollar fee based on size and shipping weight. Storage is cents per cubic foot per month with seasonal adjustments. Together they can resemble a high “effective take rate” on low ASP, heavy, or slow-moving goods, and a lower effective rate on small, light, fast-turn products. Use this tool’s breakdown table to see how each line contributes at your price point.
Worth it depends on contribution margin after all Amazon fees, your inventory velocity, and the fully loaded cost to fulfill yourself. FBA often wins on Buy Box logistics and Prime eligibility, but storage and aged-inventory risk can punish bulky or seasonal SKUs. Enter a realistic merchant-fulfilled shipping and handling estimate in the FBM field and compare profit after COGS. Add warehouse labor, returns, and packaging externally—this page keeps the comparison focused on fees you can model quickly.
Amazon bills monthly storage in cubic feet times the rate for that month and product size class (standard versus oversize in live accounts). This educational calculator uses standard-size-style cubic footage from your inches input and multiplies by either an off-peak or peak dollar rate per cubic foot. It does not simulate inventory age averaging across batches or long-term surcharge stacking with surgical precision—use the output as directional planning, then read your payments report for ground truth.
Dimensional weight is a volumetric weight Amazon uses so lightweight but bulky packages pay more to fulfill. It is computed from your package volume divided by a divisor (modeled here as one hundred thirty-nine cubic inches per pound for US FBA). Billable shipping weight is typically the greater of actual packaged weight and dimensional weight. If a small change in height pushes dimensional weight above actual weight, you can jump to a higher fulfillment bracket even though the scale weight did not change.
SynthQuery exposes the math and assumptions so you can reason about tiers, but Amazon’s live fee engine includes program-specific adjustments, promotions, rounding rules, and category edge cases we do not claim to mirror bit-for-bit. Treat outputs as planning estimates. Before inventory commitments, use the Revenue Calculator inside Seller Central and your actual fee preview for the ASIN.
Merchant fulfillment avoids FBA fulfillment and FBA storage, but most professional seller listings still incur referral fees on the item price category. You also shoulder shipping, customer service, and returns handling. The FBM column in this tool models referral plus your typed shipping estimate so you can compare channel margin skeletons before layering labor and supplies.
When you ask Amazon to return inventory from fulfillment centers or destroy unsellable units, per-item fees apply based on size and weight. Enable the removal toggle here to add an illustrative return or disposal estimate to your scenario. Actual quotes appear when you create removal orders in Seller Central.
Financial outputs tell you whether a listing is worth the fight; AI quality tools help you win the click. After you stabilize price and margin assumptions, run listing copy through the AI Detector at /detect if you need policy-aligned authenticity checks, and use the Humanizer at /humanizer to refine AI-assisted drafts so bullets and A+ style content read credible to shoppers and match your brand voice.
Browse /free-tools for the full utilities grid. For adjacent fee math, open /shopify-fee-calculator and /stripe-fee-calculator. For margin and price translation, use /markup-calculator, /cogs-calculator, /contribution-margin-calculator, and /roi-calculator. The complete product catalog—including detection, readability, plagiarism, and more—lives at https://synthquery.com/tools.