The conversion that makes quotes comparable
Parcel carriers price per box by weight and dimensions. Removalists price per cubic metre. To compare them you need one conversion: a medium tea-chest box is 0.1 m³, so ten medium boxes make one cubic metre. A small book box is half that. Now every quote is the same unit, and the maths takes one minute.
Under ~20 boxes: parcels win
A student sending ten boxes Sydney to Melbourne is parcel territory. Ten medium boxes at $15–30 each lands somewhere around $150–300, they travel through the carrier's network in a few days, and there's no minimum charge to swallow. The same ten boxes as a backload cost the $350 minimum — more money for the same outcome, unless the door-to-door pickup and included insurance are worth the difference to you.
Two parcel-side catches to price in before you decide. Weight: carriers surcharge or refuse boxes over roughly 22 kg, and a medium box packed solid with books gets there fast — split books across small boxes. And cover: parcel transit insurance is an add-on with per-item limits, so anything genuinely valuable travels better under a removalist's goods-in-transit policy.
Above ~30 boxes — or any furniture: backload wins
Thirty medium boxes is 3 m³. As parcels that's $450–900 and thirty individual labels; as a backload it's about $350 on Sydney–Melbourne — one pickup, one delivery, strapped as its own zone on the truck, insurance included. From there the gap only widens, because the lane rate is flat per m³ while parcel costs stack per box.
And the moment furniture enters the picture, the comparison ends. A queen bed, a sofa and twenty boxes is about 7 m³ — around $700 backloaded Sydney–Melbourne — and no parcel network will take the bed anyway. If even one item on your list can't go in a box, get the backload quote first and let the boxes ride along at the lane rate.
- ≤ 15–20 medium boxes, all under 22 kg: book a parcel carrier
- 30+ boxes: the $350 backload minimum is already competitive
- Any furniture at all: backload — the boxes ride along per m³
- Books: always small boxes, or the weight surcharge finds you
Either way, pack like it's freight
Interstate boxes get handled more times than a local move's do. Double-tape the bottom seam, fill boxes completely (half-empty boxes crush under stacking), label the destination room, and keep documents, chargers and medication out of the shipment entirely. If your boxes-only move might grow into a furniture move — it usually does — add up your real cubic metres with the calculator before you book anything, and check what can't travel interstate so nothing gets pulled at pickup.