A 16x20 patio is 320 square feet, and the 20 foot run is what buys the layout: a dining zone at one end, a lounge zone at the other, and a walkway between them. This is the size people pick when the patio has to be two rooms.
Worked math at the example rates
These are the example rates from our demo calculator. They exist to sanity-check a quote, not to predict your local market.
| Finish | Example rate | 16x20 (320 sq ft) |
|---|---|---|
| Standard broom | $9 / sq ft | $2,880 |
| Colored | $12 / sq ft | $3,840 |
| Stamped | $16 / sq ft | $5,120 |
Look at the spread. At this size the gap between example broom and example stamped is $2,240, which is real money riding on a finish decision. That is why the border trick shows up at exactly this scale: stamp a decorative band around the perimeter, broom the field, and land between the two numbers. Stamped vs plain concrete digs into when the full upgrade earns its cost.
What moves the number off the table
- Tear-out. Existing concrete or pavers out first: an example $4 per square foot, $1,280 on 320 square feet.
- Site prep and grading. An example $2 per square foot, $640. A 20 foot run makes grade problems more likely, since yards rarely stay level that long.
- Sealing. Another example $2, $640, most worthwhile over colored or stamped surfaces.
- Access. At the typical 4 inch patio thickness this is about 4 yards of concrete. If the truck cannot reach the back of a 20 foot pour, plan on a pump.
Patio thickness, briefly
Four inches is the standard patio pour, because furniture and foot traffic are light duty. Vehicles are the reason driveways go thicker. If a corner of this slab will carry something heavy, a hot tub or a masonry kitchen, flag it before forming, not after.
Pricing the same footprint as a garage or utility slab instead? See the 16x20 concrete slab page. For any other patio size, the concrete patio cost calculator takes custom dimensions.
If you quote this work, PriceDesk runs the same calculator with your rates and your add-ons. Free for 14 days.