OUR METHODOLOGY

Clear numbers start
with clear assumptions.

The calculator estimates a single sale using the rates and amounts you enter. Use the final item price after seller-funded coupons; do not subtract that coupon again as a seller cost. It does not connect to your Whatnot account.

What we calculate

• Commission: the supported item-price base × your selected category/current-tier rate, or your custom rate.
• Processing: (item price + buyer-paid shipping + buyer-paid tax) × processing rate + the fixed processing fee.
• Seller proceeds: item sale price − commission − processing − modeled tax on seller fees.
• Profit: proceeds − item cost − other seller costs. Profit remains unknown until you enter an item cost.

What the starting rates mean

Category choices use the current country rate card and the locked tier you select under Rates & extra costs. Standard is the starting choice. Use Custom rate for a negotiated rate. The tool never infers a new tier from a proposed sale or connects to your account.

The starting values are editable assumptions informed by Whatnot’s fee documentation, consulted on October 16, 2026. They do not determine your current category, commission tier or special agreement. Use the rates from your actual receipt.

For Canada, amounts and the starting CA$0.30 fixed processing fee use CAD. Whatnot’s CAD migration guidance confirms that Canadian sellers moved to CAD in April 2025. Historical USD receipts are outside this calculator’s scope.

Rounding and limits

Supported high-value discounts cap the commission base for eligible categories/formats while preserving the full payment-processing base. CAD is excluded until an official CAD threshold is established. The AU fashion-week option is limited to October 18–24, 2026 and its eligible categories; accepted offers must also have been submitted during that period. A qualifying zero-commission week takes priority over a cap. Unsupported or missing eligibility facts produce an explanation rather than an invented estimate.

Fee tax supports an exact receipt amount, separate entered rates on commission and processing, or UK/AU VAT/GST registration status. Each calculated fee-tax line is rounded to cents before summing. This models platform-collected charges only; your own sales/income tax liability and recoverable tax are outside the profit estimate.

The initial fee-tax amount is an assumed zero, not a receipt or a tax exemption. UK/AU results identify excluded VAT/GST beside the estimate. Choose the registered treatment only after your tax number has been added and validated by Whatnot. Registration awaiting validation does not establish a zero-collection result.

Sales Tax Rate estimates additional buyer tax on the item price, or on price plus shipping if you select that option. Estimated tax is rounded to cents before processing fees are calculated. You can instead enter the exact additional tax amount from a receipt. If tax is already included in your entered price, use zero additional tax. Local tax rules and seller tax liabilities are not determined by this calculator.

We use decimal arithmetic and round each commission and processing amount to two decimal places, half up. This is an estimate convention; receipt-level rounding still needs verification. Amounts are limited to 1,000,000 in the selected currency.

Buyer-paid shipping and buyer-paid tax are used for processing fees, not treated as seller revenue. Each estimate represents one charged sale; combining separately purchased items into one shipment does not merge their processing fees. Refunds, giveaways, currency conversion and unmodeled promotions are outside this version. Reviewed presets cover sale dates from October 16, 2026. Earlier receipts are unsupported: historical promotions can differ even when base rates are unchanged.

What is being verified next

The break-even calculator finds the lowest positive cent price that covers entered costs, reaches a target profit, or reaches a target profit margin. Margin is profit divided by item price, not markup. Current tier stays fixed. Percentage buyer tax scales with price; receipt tax amounts stay fixed. The same fee engine verifies every suggested price. Invalid, unsupported or unreachable goals do not produce a price. A bounded search also stops without claiming a minimum if unusual rates need more work.

Independent country-rule review, receipt-level rounding and real-browser verification are still pending. State/province/city tax lookup and your own tax liabilities are not automated. The country packs remain draft; this is not yet a verified production fee calculator.