Across the US, the average deck cost per square foot ranges from $20 to 40. depending on the material you install. //-->. Deck and Railing Cost Calculator. Deck Cost Calculator. All numbers should be entered as real numbers which are bigger than 0 (zero) for specific value or equal to zero for no value parameters. These require almost no maintenance, just occasional washing to keep it looking nice and clean. google_ad_slot = "8903491512"; Deck cost calculator computes project size, average completion time, and total cost to build a new deck. At our age we can read a person well enough. Building a small deck typically costs around $4,000 on average, a mid-sized deck’s price is around $7,000, whereas the average price for a large deck is from $9,000 or more. When searching for a perfect deck, its important to consider aesthetics. It’s not only me who is looking after the budget before going to a home renovation. and 10 posts. Get an estimate of how much it would cost to build your custom dream deck with Trex's deck cost calculator.