Start with dig depth, not sticker price
The single most important specification on a mini excavator is maximum digging depth. Measure the deepest point your average job requires, then add a 10% safety margin. A CR12 digs to 2.22 m; a CR18 to 2.38 m. If your water lines or foundations run deeper than that, step up a class.
Depth drives boom and arm length, which also determines reach, lift capacity and how the machine feels when you swing a full bucket. Buying for depth first means you buy once.
Match width to the gates you must pass
Every urban job starts with a gate. Measure the narrowest opening a machine must pass through — including a margin for the operator to steer. Machines under 1.2 t commonly offer 720–1,000 mm widths and telescopic undercarriages.
If you regularly work through fences and doorways, a zero-tail-swing machine under 1,500 mm is the practical choice. For open sites, a wide stance buys stability and lift capacity.
Transportability changes the economics
A 0.8–1.8 t machine tows behind a pickup or small trailer — no special permits, no lowboy. The 2.5–6 t class generally needs a proper towing rig or flatbed. Crunch the transport cost per job, not just the machine price.
Many buyers keep a CR08 for indoor work and a CR35 for outside production, covering the full range with two machines that each tow easily.