AC Replacement Cost Calculator

How much does AC replacement cost in 2026?

Replacing a central air conditioner is one of the most common and significant home expenses in the United States. The installed price depends on four variables: the size of the system (measured in tons), the efficiency rating (SEER2), your state’s labor and permit costs, and whether the job requires new ductwork or only a straight equipment swap.

Typical cost by system size

Smaller systems cost less, but the savings are not linear — labor, refrigerant, and permits are relatively fixed regardless of tonnage. A 2-ton unit serving a smaller home or condo typically sits at the low end of the range. A 3-ton system covers most mid-size homes and represents the most common replacement. A 4 to 5-ton unit for a larger home pushes toward the top of the range, with the equipment cost and refrigerant charge both scaling up. Use the calculator above to see the range for your specific size and state.

What drives the price up

Three things reliably push a replacement above the typical range. First, new ductwork: if your existing ducts are damaged, undersized, or absent, adding or replacing them can add several thousand dollars to the project. Second, high-efficiency equipment: a 20 SEER2 unit costs meaningfully more than a code-minimum 14.3 SEER2 system, though the running-cost savings can offset that premium over time in hot climates — check with the SEER2 savings calculator. Third, access difficulty: if the indoor unit is in a tight attic, crawlspace, or high-rise building, labor hours increase.

Replacement vs repair

If your existing AC has failed, the question is whether to fix it or replace it. The general guideline: if the repair costs more than half the price of a new system, or the unit is past about 12 years old, replacement is usually the better long-term value. A newer unit will also be more efficient, lowering your monthly bills. For a deeper walkthrough of this decision, see our guide to AC repair vs replace.

Frequently asked questions

How much does it cost to replace a 4-ton AC unit?

A 4-ton central AC replacement typically falls in the upper-middle portion of the range for your state. Use the calculator above, set the size to 4 ton, and select your state for a tailored estimate.

How much does AC installation cost without ductwork?

If you have existing ductwork in good condition, a straight equipment swap is the standard price shown above. If new ductwork is needed, expect the total to increase significantly — the calculator includes a ductwork option to estimate this.