How much does an AC replacement cost in Saint Peters, MO?
US national rangeUpdated Prices checked October 20262 sources
An AC replacement costs $3,887 to $8,073 nationally, typical $5,978. We have no documented price index for Saint Peters for this job, so this is the US national range from HomeAdvisor, checked October 2026.
US national range, not adjusted for this city
- Low
- $3,887
- Typical
- $5,978
- High
- $8,073
AC replacement cost in Saint Peters, MO
We have no documented price index for Saint Peters for this job, so the table shows the US national range.
| Estimate | Low | Typical | High | Basis | Checked |
|---|---|---|---|---|---|
| US national range | $3,887 | $5,978 | $8,073 | Per system, installed (unit plus labor); typical range of customer-reported jobs (HomeAdvisor) | October 2026 |
AC replacement cost by type or size
US national figures in USD, as published by each source.
| Type or size | Price (USD) | Source |
|---|---|---|
| 3-ton central AC replacement, existing ducts | $5,500 to $10,000 | Fixr |
| 3-ton central AC replacement with new ducts | $7,500 to $16,000 | Fixr |
What drives the cost of an AC replacement
System size
Capacity in tons depends on home size, climate, sun exposure and insulation.
Efficiency (SEER2)
Higher-efficiency units cost more up front and less to run.
Ductwork
New ductwork is the largest add-on, at $1,000 to $5,000.
System type
Split, packaged, heat pump and ductless systems are priced differently.
Electrical and drain work
A panel upgrade or new condensate line adds cost.
Labor
Installation typically takes four to eight hours, about $300 to $1,600 in labor.
Permits and what's included in Saint Peters
Permit note
A mechanical or electrical permit and an inspection are usually required. Ask whether the quote includes them.
Rules are set locally; confirm with Saint Peters’s building department.
What’s usually included
- The new outdoor and indoor equipment
- Refrigerant lines, electrical connection and startup
- Removal of the old unit (confirm on the quote)
Scopes vary. Get the scope in writing on every quote.
Get AC replacement quotes in Saint Peters
Tell us about the job and we will pass it to local pros. Asking for quotes never changes how we rank anyone.
Two short steps: your name, then how to reach you. Free, and it never changes anyone’s rank.
Top-ranked HVAC contractors in Saint Peters
The top 3 of 340 HVAC contractors we rank for Saint Peters, MO, by CR Score. Paid placement never changes rank.
- #1Jerry Kelly Heating & Air ConditioningCR Score 674.9from 6,530 Google reviews
- #2Air Comfort Service Inc.CR Score 665.0from 1,159 Google reviews
- #3Stay Cool Climate ControlCR Score 655.0from 1,068 Google reviews
AC replacement cost in Saint Peters: questions
How much does an AC replacement cost in Saint Peters, MO?
Do I need a permit for an AC replacement in Saint Peters?
What affects the cost of an AC replacement?
How many HVAC contractors serve Saint Peters?
What is usually included in the price?
Sources
Checked October 2026. Figures are estimates, not quotes.
- HomeAdvisor: AC unit installation cost · page updated June 17, 2026 · checked October 2026Primary source. Used for: Low, typical and high; ductwork, labor and efficiency drivers.
- Fixr: Central air conditioner installation cost · page updated August 29, 2025 · checked October 2026Used for: 3-ton replacement ranges with and without new ducts; drivers; permit.
Related pages
More cost guides for Saint Peters
- Roof replacement cost in Saint Peters
- Roof repair cost in Saint Peters
- Water heater replacement cost in Saint Peters
- Furnace replacement cost in Saint Peters
- Electrical panel upgrade cost in Saint Peters
- Interior painting cost in Saint Peters
- Exterior painting cost in Saint Peters
- Kitchen remodel cost in Saint Peters
- Bathroom remodel cost in Saint Peters
- Hardwood floor installation cost in Saint Peters
- Fence installation cost in Saint Peters
- Deck building cost in Saint Peters
- Siding replacement cost in Saint Peters
- Window replacement cost in Saint Peters
- Gutter installation cost in Saint Peters
- Attic insulation cost in Saint Peters
- Solar panel installation cost in Saint Peters
- Garage door repair cost in Saint Peters
- Foundation repair cost in Saint Peters
- Tree removal cost in Saint Peters
- Water damage restoration cost in Saint Peters
- Concrete driveway cost in Saint Peters
- Drywall repair cost in Saint Peters