Holding the route constant is the only way to see where a shipment changes category.
The test, and what came back
Three shipments, all from Newark, NJ 07102 to Atlanta, GA 30303, all captured on 2026-07-28 through the SMKlog calculator. Nothing was changed except the box and the weight on it.
| Shipment | Parcel rates returned | Cheapest parcel price | What the system did |
|---|---|---|---|
| 24 x 18 x 18 in, 70 lb | 5 | $79.61 | Parcel label ready to buy |
| 30 x 24 x 24 in, 150 lb | 0 | none | No rates shown: freight, which SMKlog does not arrange |
| 48 x 40 x 40 in, 300 lb | 0 | none | No rates shown: freight, which SMKlog does not arrange |
The line is not fuzzy. One side of it is a checkout with five options and a printed label; the other side is a freight carrier collecting cargo details, which SMKlog does not do. Carriers draw it at the same place: UPS stops at 150 lb and FedEx classifies a shipment as freight above 150 lbs, both checked on their own sites on 2026-07-28.
What the last parcel-priced box looked like
Worth seeing in full, because 70 lb is where parcel economics start to hurt. Five services, one carton, the same day and lane as the table above.
| Carrier | Service | Price | Quoted transit |
|---|---|---|---|
| FedEx | Ground Economy | $79.61 | 6-7 business days |
| UPS | Ground | $81.27 | 2-3 business days |
| UPS | Ground Saver | $83.08 | no window given |
| UPS | 3 Day Select | $120.19 | 5-6 business days |
| FedEx | Ground | $150.67 | 5-6 business days |
Compare that with the lighter box on the same lane and day. A 50 lb carton quoted $45.01 with UPS Ground; adding 20 lb and four inches of height nearly doubled the UPS Ground figure to $81.27. Parcel gets less efficient as a shipment grows, which is precisely the opposite of what freight does, and that divergence is why the crossover exists at all.
Choosing when you are near the line
Under 150 lb, splitting usually wins
Two 60 lb cartons will nearly always beat one 120 lb crate on a parcel network, because each stays under the handling triggers and neither is oversize. Splitting also keeps the shipment inside a system with door-to-door tracking on every piece, which pallets do not give you by default.
Over 150 lb, density starts paying
Freight prices from class, and class comes from pounds per cubic foot, so a dense pallet is cheaper per pound than a light one of the same size. The same instinct that saves money in parcel, making the box smaller, saves money in freight too, but for a completely different reason.
Count the ends, not just the middle
A parcel price includes the doorstep. A freight price often does not: liftgate service and non-commercial delivery are quoted as extras, and a house with no dock needs both. Before you decide the truck is cheaper, ask what happens in the last fifty feet.
What each side of the line buys you here
We sell US domestic parcel labels with no account and no subscription, and the price you see is the price collected. SMKlog sells parcel labels only and does not arrange pallet or freight shipments. We do not sell full truckload, cross-border freight, warehousing or fulfilment either.
Crossover questions
At what weight does parcel stop and freight start?
150 pounds for a single package. UPS publishes a 150 lb maximum and FedEx classifies a shipment as freight above 150 lbs, both checked 2026-07-28, and our own calculator matched them: a 70 lb carton returned five prices while 150 lb and 300 lb returned none.
Is LTL cheaper than parcel for a heavy shipment?
Often, once the load is dense and palletized, because freight prices from class rather than from volume alone. Below the 150 lb line parcel usually wins on total cost and always wins on simplicity, since the price includes the doorstep and every piece is tracked.
What did a 70 lb box cost on your test lane?
Five services came back for a 24 x 18 x 18 in carton at 70 lb from Newark, NJ 07102 to Atlanta, GA 30303 on 2026-07-28, from $79.61 with FedEx Ground Economy up to $150.67 with FedEx Ground. UPS Ground sat at $81.27 with a 2-3 business day window.
Should I split a heavy shipment into several boxes?
If the total stays under 150 lb and each carton stays inside the size ceilings, yes. Two 60 lb cartons keep the shipment in the parcel network with tracking on each piece, and avoid the handling and large package triggers that a single oversize carton would hit.