Running a central air conditioner in a typical Texas home costs roughly $90 to $230 per month during summer, depending on your unit's size, your home's efficiency, and the rate on your electricity plan. That wide range exists because two variables swing the math dramatically: how many kilowatt-hours your unit consumes and how many cents you pay per kilowatt-hour. This article works through both.
The Formula You Need
The cost of running any appliance comes down to one equation:
Daily cost = (Wattage / 1,000) x Hours of operation x Rate in cents per kWh / 100
For a central AC unit, the wattage is the compressor draw, not the blower alone. A 3-ton central unit (the most common size for Texas homes in the 1,500 to 2,000 square foot range) draws roughly 3,500 watts when the compressor is running. A 2-ton unit draws around 2,300 watts; a 5-ton unit can exceed 5,800 watts.
The compressor does not run continuously. In mild weather it might cycle for four to six hours a day. On a 100-degree August afternoon in Dallas or Houston, that same unit may run eight to twelve hours or more.
A Worked Example at Common Texas Sizes
Assume a rate of 14.7 cents per kWh, which is the median listed rate at 1,000 kWh across plans on Choose My Power as of October 2, 2026.
2-ton unit (2,300 watts), 8 hours of run time per day:
- Daily kWh: 2.3 x 8 = 18.4 kWh
- Daily cost: 18.4 x 14.7 cents = $2.70
- Monthly cost (30 days): $81
3-ton unit (3,500 watts), 8 hours per day:
- Daily kWh: 3.5 x 8 = 28 kWh
- Daily cost: 28 x 14.7 cents = $4.12
- Monthly cost: $124
4-ton unit (4,600 watts), 10 hours per day:
- Daily kWh: 4.6 x 10 = 46 kWh
- Daily cost: 46 x 14.7 cents = $6.76
- Monthly cost: $203
These figures cover the compressor only. Add the air handler blower (typically 300 to 500 watts running continuously while the system is on) and the real monthly number edges up another $10 to $20.
Why Your Rate Matters as Much as Your Equipment
The equipment calculation above used 14.7 cents per kWh. But rates on the Texas market span a wide range. As of October 2, 2026, the cheapest plan listed on Choose My Power sat at 6.6 cents per kWh all-in at 1,000 kWh (APGE SimpleSaver 12, in the lowest-cost utility area). The most expensive plans on the same snapshot ran above 20 cents per kWh.
Run the 3-ton unit example again at both ends:
- At 6.6 cents: $55 per month
- At 14.7 cents: $124 per month
- At 20 cents: $168 per month
The unit is identical. The rate difference accounts for a $113 monthly swing. Over a five-month Texas cooling season (May through September), that is more than $560. Choosing the right plan matters as much as buying an efficient unit.
Window Units and Mini-Splits: Smaller Footprint, Different Math
Not every Texas household runs central air. Window units and ductless mini-splits have smaller compressors and therefore lower per-hour draw, but they often cool smaller spaces.
A 12,000 BTU (1-ton) window unit draws roughly 1,100 to 1,200 watts. At 8 hours of daily run time and 14.7 cents per kWh, that is about $42 per month. A home using three window units to cover three rooms approaches or exceeds the cost of a modest central system.
Mini-split systems are generally more efficient than window units of comparable size because they use inverter-driven compressors that modulate output rather than cycling on and off. A single-zone 12,000 BTU mini-split might draw 800 to 950 watts at partial load, reducing monthly cost to roughly $28 to $34 under the same assumptions.
SEER Rating: The Efficiency Number That Changes the Cost
SEER (Seasonal Energy Efficiency Ratio) measures how much cooling a unit delivers per unit of energy consumed. The federal minimum for new central systems sold in the South and Southwest (the SEER2 standard, in effect since January 2023) is 14.3 SEER2 for split systems under 45,000 BTU/h, the equivalent of the old 15 SEER. Many units sold today hit 16 to 18 SEER2. High-efficiency units reach 20 to 24 SEER2.
A higher SEER rating means fewer kWh consumed for the same amount of cooling. A 3-ton unit rated at 14 SEER (an older standard) might draw 3,500 watts. The same 3-ton capacity at 18 SEER2 might draw 2,700 watts, reducing monthly cost from $124 to roughly $95 at the median rate. Over a full cooling season, that gap compounds.
When comparing replacement equipment, divide the purchase price premium for the higher-efficiency unit by the annual savings to calculate payback period. In Texas, with long cooling seasons, payback periods of four to seven years are common for moving from a 14 SEER to an 18 SEER unit.
The Thermostat Setting Has a Larger Effect Than Most People Expect
A widely cited industry rule of thumb holds that each degree of thermostat setback (raising the cooling setpoint) saves roughly 1 to 3 percent on cooling costs. The U.S. Department of Energy's own figure is that you can save as much as 10 percent a year on heating and cooling by turning the thermostat back 7 to 10 degrees for 8 hours a day. The actual figure depends on how well the home is insulated and how hot the outdoor air is relative to indoor air.
In practical terms, moving a thermostat from 72 degrees to 76 degrees in a Texas summer reduces the temperature differential the system must maintain and cuts compressor run time meaningfully. For a home spending $150 per month on AC, that shift can reduce costs by roughly $6 to $18 per month, with no equipment change and no plan switch required.
A programmable or smart thermostat that raises the setpoint when the home is unoccupied amplifies these savings further.
Duct Leakage: The Hidden Multiplier
ENERGY STAR estimates that in a typical home, about 20 to 30 percent of the air moving through the duct system is lost to leaks, holes, and poorly connected ducts, with losses running higher where ducts sit in hot, unconditioned attics, as they do in most Texas homes. A unit that should deliver 3 tons of cooling effectively delivers 2 tons or less when ducts leak into unconditioned attic space.
If a home has significant duct leakage, the compressor runs longer to compensate. The cost impact is equivalent to overpaying for a less efficient unit. A duct test and seal by a certified HVAC technician (typically $300 to $800) can pay back in one or two cooling seasons in a leaky home.
How Your Electricity Plan Structure Affects the Real Cost
The rate on the bill is not always the same as the headline rate in an advertisement. Texas plans often include bill credits that apply only when usage hits a specific threshold, typically 1,000 kWh or 2,000 kWh per month. Below that threshold, the effective rate is higher.
As of October 2, 2026, 14 of the 125 plans listed on Choose My Power carried a bill-credit cliff where a bill at 500 kWh ran $25 or more above the same plan's bill at 1,000 kWh. A household with a small AC unit or a well-insulated home that stays below 1,000 kWh may pay more per effective kWh than the plan's headline rate suggests.
Before switching plans, use a plan's Electricity Facts Label to calculate your bill at your actual usage level, not the advertised benchmark.
The Short Version
AC operating cost in Texas depends on four things: unit size and efficiency, hours of operation, duct condition, and the rate on your electricity plan. The median plan on the Texas market charges 14.7 cents per kWh, which puts a typical 3-ton unit at roughly $90 to $160 per month during peak summer months. Households on higher-rate plans or running older, inefficient equipment can push well above $200. Checking the plan rate, testing duct integrity, and setting the thermostat conservatively are the three levers most households can act on without replacing any equipment.