How our calculations work

Input-first calculations

Our calculators use only the figures entered by the visitor. We do not supply hidden carrier rates, tax rates, legal thresholds or marketplace fees. Currency selection changes display formatting; it does not perform exchange-rate conversion.

Return-cost model

The central model adds refund, shipping, handling and other non-recoverable costs, then subtracts realistic recovered inventory value. Recovery should reflect what the business expects to regain through resale, refurbishment or liquidation—not the original retail price.

Returnless-refund comparison

The returnless tool compares the estimated cost of accepting a physical return with the proposed keep-item refund. The true break-even keep-item refund is where both options have the same modeled cost; it can exceed the customer's full refund. It is not a recommendation or eligibility decision. Product safety, fraud controls, warranty obligations and customer history remain outside the formula.

Partial-refund model

The partial-refund tool begins with the item price plus the exact tax and original-shipping amounts marked refundable, then subtracts entered fees and deductions. Tax reversals can be transaction- and jurisdiction-specific, so the refundable-tax input must come from the seller's payment or tax system. The calculator does not determine whether deductions are lawful or permitted by a marketplace.

Restocking-cost model

The restocking estimate adds return shipping, inspection and repackaging costs to expected depreciation. The result is capped at item price and is presented as an internal cost estimate. A permitted customer fee may be different or unavailable entirely.

Return-rate forecast

The forecast uses an order-level return rate: returned orders divided by fulfilled orders for the same period. This differs from item-based metrics such as returned units divided by sold units. It converts the order rate into expected returned orders, applies a net cost per return and annualizes the monthly estimate. Peak seasons and materially different categories should be modeled separately.

Rounding

Calculations use full numeric precision internally and display monetary results to two decimal places. Cost comparisons use displayed cent precision so a visually equal result is never presented as a cheaper option. Percentages and expected order counts may be rounded for readability.

Validation protocol

Every formula is compared with a separate hand-calculated example. We also test zero inputs, percentage boundaries, deductions above refundable value, equal-cost decisions and cases where recovery exceeds gross cost. Calculator output is constrained where a negative refund or cost would not be meaningful.

Editorial review and corrections

The Refund or Return editorial team reviews the formula, field labels, worked example and limitations together. When a calculation changes, the related guide and example are updated in the same release. Report suspected errors through the contact page.

Limitations

Results exclude any cost not entered, including chargeback risk, future customer value, fraud probability, taxes, currency conversion, platform-specific reimbursements and contractual carrier adjustments. Use the result as one input to a documented business decision.

Last reviewed: August 17, 2026.