A 20x20 patio is 400 square feet, a full outdoor living space. Dining table, sectional, grill station, fire table: at this size the patio stops being a feature of the yard and starts being the yard. The price math is still square footage times a finish rate, so start there.
400 square feet at example rates
| Finish | Example rate | 20x20 (400 sq ft) |
|---|---|---|
| Standard broom | $9 / sq ft | $3,600 |
| Exposed aggregate | $13 / sq ft | $5,200 |
| Stamped | $16 / sq ft | $6,400 |
Every number above is an example rate from our demo calculator, there for scale, not a market price. What the table shows well: at 400 square feet, each dollar of rate difference is $400 on the bottom line, so the finish conversation is the budget conversation.
What 400 square feet means on pour day
Two realities specific to this footprint. First, at the typical 4 inch patio thickness you are placing about 5 yards of concrete, which is still a one-truck pour but a real day of finishing work, and stamped finishing at this scale needs extra hands moving fast. Second, a 20 foot square is past the joint spacing a 4 inch slab can carry, so it gets cut into quadrants. Those joint lines and the drainage slope away from the house both get decided during layout, and both are worth asking about before the forms are set.
Moving off the table math
Tear-out of an existing slab adds an example $4 per square foot, a serious $1,600 at this size. Site prep and grading is an example $2, $800, and big footprints are more likely to need it because few yards are flat for 20 feet in both directions. Sealing at an example $2 is another $800 over decorative work. Access matters as much as ever: the farther the truck parks from the forms, the more the labor line grows.
Weighing materials at this scale? Pavers vs concrete patio covers that call. The same footprint as a utility slab is on the 20x20 concrete slab page, the full pricing method is in how to price a concrete patio, and the concrete patio cost calculator handles any size between the ones on this site.
Contractors: swap the example rates for your own and this quote takes about ten seconds on your phone. The PriceDesk trial is free for 14 days.