Agentis analysis of USPS's own published Ground Advantage pricing confirms rates start at $7.90 at a Post Office location. A merchant charging a flat $4.99 shipping fee absorbs at least $2.91 of that cost per order before any packaging or handling, an amount that comes straight out of gross margin on every single sale, not just the unprofitable ones.
What you charge the customer for shipping, including $0 for free shipping.
USPS Ground Advantage starts at $7.90; your actual cost depends on package weight and zone.
Shipping Subsidy Per Order
$2.91
Total Monthly Subsidy Cost
$1,455.00
| Service | Starting Rate | Note |
|---|---|---|
| USPS Ground Advantage | $7.90 | Starting price at a Post Office location; actual rate varies by weight (tiered at 4oz/8oz/12oz/15.999oz increments up to 1 lb, then by the pound) and shipping zone |
Source: USPS: Ground Advantage (retrieved August 7, 2026). $7.90 is USPS's stated starting price, not a flat rate. It represents the floor for the lightest, shortest-zone packages; most orders cost more to ship than this figure.
| Flat Rate Charged | Actual Cost (USPS Starting Rate) | Subsidy Per Order | Subsidy on 500 Orders |
|---|---|---|---|
| $0 (free shipping) | $7.90 | $7.90 | $3,950 |
| $2.99 | $7.90 | $4.91 | $2,455 |
| $4.99 | $7.90 | $2.91 | $1,455 |
| $5.99 | $7.90 | $1.91 | $955 |
| $7.90 (break-even) | $7.90 | $0.00 | $0 |
Source: USPS: Ground Advantage (retrieved August 7, 2026). Agentis synthesis: the gap between USPS's published $7.90 starting rate and common flat-shipping price points, scaled across a representative 500-order month. Actual per-order cost is typically higher than $7.90 once weight and zone are factored in, so these figures understate the subsidy for most real orders.
How we calculate this
USPS's own Ground Advantage pricing page states rates start at $7.90 at a Post Office location; actual cost varies by weight and zone. The subsidy figures are Agentis synthesis: the gap between that starting rate and common flat-shipping price points, scaled across a representative monthly order volume. Read our full methodology →
Expert Insight
Free shipping and flat-rate shipping both work as conversion levers. The problem is merchants price them off what feels competitive, not off what USPS actually charges. Every flat rate below the carrier's real cost is a fixed subsidy baked into every single order, profitable or not, and it scales with volume the same way a per-unit COGS increase would. A $2.91 gap on 500 orders a month is $1,455 in margin that never shows up as a line item anywhere, because it's hiding inside 'shipping revenue' instead of being tracked as a shipping cost overrun.
Herzel Mishel, CEO & Co-Founder →No. $7.90 is USPS's published starting price for Ground Advantage at a Post Office location. The actual rate for a specific package depends on its weight and shipping zone, and typically runs higher for heavier packages or longer distances. $7.90 is the floor, not a flat rate you should expect to pay on every order. USPS tiers Ground Advantage by weight at 4 oz, 8 oz, 12 oz, and 15.999 oz up to one pound, then by the pound, and by shipping zone. The starting rate therefore describes the lightest, shortest-zone packages only. That makes the subsidy figures on this page conservative: a $4.99 flat rate absorbs at least $2.91 per order, or $1,455 across 500 monthly orders, and free shipping absorbs at least $7.90, or $3,950. To measure your own subsidy, pull the average label cost you actually paid last month and subtract the shipping fee you charged.
Agentis analysis of UPS's and FedEx's own published 2025-2026 peak-season surcharge schedules shows a standard residential Ground package's demand surcharge nearly doubles during the highest-volume week: from $0.40 to $0.60 at UPS, and from $0.50 to $0.80 at FedEx. USPS publishes no equivalent add-on surcharge.
Agentis analysis of Shopify's own discount-combination documentation confirms an order-level discount code combines with a free-shipping discount by default, no special setup required. On an $80 order with 40% gross margin, a 20% discount code cuts gross profit from $32 to $16, and stacking an $8 shipping cost on top drops it to $8, a 75% cut in what the order was expected to earn.
Agentis analysis of USPS's own published rates confirms Priority Mail starts at $11.00 per package versus Ground Advantage's $7.90, a $3.10 premium for a 2-3 day delivery estimate that carries no money-back guarantee. Defaulting every order to Priority Mail instead of Ground Advantage costs an extra $1,550 a month on 500 orders, without a single dollar of that showing up as a line item most merchants track.
Agentis finds margin leaks automatically.
Data last updated August 7, 2026. Browse all Shipping & Fulfillment pages →