On a $35 sale, Poshmark's 20 percent commission takes about $7, Depop's roughly 10 percent marketplace fee plus payment processing takes close to $5, and Mercari sits between them depending on its current rate. The cheapest app depends heavily on your price point.
How the three differ
Poshmark is the simplest. Sales under $15 pay a flat $2.95. At $15 and above it is a 20 percent commission. Shipping is a flat rate paid by the buyer, so it rarely comes out of your earnings.
Depop charges a marketplace fee of around 10 percent plus payment processing near 3.3 percent and $0.45 in the US. Critically, both are charged on the total including shipping.
Mercari has changed its structure several times, moving between 10 percent, zero, and back again. Whatever you read, check the current rate before pricing.
Because these move so often, all three calculators keep the rates as editable fields: Depop, Poshmark and Mercari.
The flat fee changes everything at low prices
Poshmark's $2.95 flat fee below $15 is brutal on cheap items. On a $10 sale that is 30 percent. On a $14.99 sale it is 20 percent. But at $14 versus $15 the seller keeps more at the higher price, because crossing the threshold swaps a $2.95 flat fee for a $3.00 commission on a larger sale. Pricing just under $15 is almost always a mistake.
Which to choose
Poshmark suits mid-priced clothing where the flat shipping rate and buyer protection justify the commission. Depop suits lower-priced streetwear and vintage where its audience is strongest, provided you remember fees apply to shipping. Mercari is broadest in category range and worth a check whenever it runs a promotional fee period.
Most successful resellers cross-list rather than choosing. The overhead is in inventory tracking, not in fees.
Price backwards, not forwards
Decide the profit you want, add your item and postage cost, then divide by roughly 0.87 to cover a 10 percent marketplace fee plus processing, or 0.80 for a 20 percent commission. That gets you a price that survives the fee instead of one you regret. The Markup vs Margin Calculator does the arithmetic, and this post explains why adding a percentage to cost gives the wrong answer.