The core idea of this page: buy the excavator the job needs, not the biggest machine in budget. Fix the operating weight from the work (dig depth, lift, ground pressure), then match the bucket and attachment to your cycle target — and price the total cost of ownership, not the sticker.
The golden rule: define the job first
Before any spec, list the work: trenching, basement excavation, loading trucks, demolition, grading. Then note the material (hard rock needs breakout force; soft ground needs low ground pressure) and the site constraints (gates, overhead clearance, swing room). The machine follows the job — not the other way around.
Machine classes and where they fit
Mini excavators (under 6 t) fit tight urban and utility work. Compact/midi (6–10 t) suit general site work. Standard machines (13–20 t) are the all-round production class. Large machines (20–40 t) handle mass earthmoving and quarry work, and over 40 t is mining territory. Wheeled excavators add road mobility; long-reach and demolition variants serve specialist jobs.
How to pick the right tonnage class
Operating weight sets dig depth, lift and ground pressure. A Cat 336 at 36,800 kg out-lifts a 20-tonne machine but costs more to move and run. Match the class to your deepest trench, your heaviest lift and the ground the site can support — then confirm the working envelope (dig depth, reach at ground level, dump height) covers your job.
The specs that decide productivity
Bucket capacity (m³) sets how much each cycle moves; breakout force (kN) sets whether the machine can break the material. Read the lift chart for how much it lifts at reach. Check auxiliary flow (l/min) and pressure (bar) before buying attachments, and confirm the engine meets your region's emissions tier (EU Stage V / EPA Tier 4 Final / China Non-road Stage IV).
What an excavator actually costs
Fuel and undercarriage wear are the two biggest running costs, then hydraulic maintenance and bucket/teeth. Purchase price is only the entry cost — a cheap machine with a worn undercarriage can cost more per hour than a new one. For the new-vs-used trade-off and a used-machine checklist, see New vs Used Excavator.
Rent, buy or lease
Below a certain annual utilisation, renting is cheaper; above it, buying wins. A rough anchor: if the machine runs most days, buy; if it runs occasionally, rent. Financing spreads the cost but adds interest — compare the total, not the monthly payment.
Frequently asked questions
What size excavator do I need for a house foundation?
Usually a compact or 20-tonne-class machine, depending on depth and access — a mini or midi for tight lots, a standard machine for deeper basements.
How much does a 20-tonne excavator cost?
Prices vary widely by brand, configuration and market; treat any figure as order-of-magnitude and quote the exact spec and attachments.
Should I buy the biggest machine that fits my budget?
No — an oversized machine burns more fuel and tears up the site. Buy the class the job needs.
Last verified: September 10, 2026.