finance calculator

AC Cost Calculator

Estimate daily and monthly energy cost for an air conditioner by BTU, SEER, and usage.

Results

Daily energy (kWh): 6.86
Monthly energy (kWh): 205.71
Monthly cost: $31 USD

How to use this calculator

Enter AC BTU, SEER/EER, hours per day, days per month, and electricity rate.
Review daily and monthly kWh plus monthly cost.

Inputs explained

Cooling capacity (BTU): AC tonnage in BTU/hr (e.g., 12,000 BTU ≈ 1 ton).
SEER/EER: Efficiency rating; higher SEER/EER = lower wattage for same BTU.
Hours per day / Days per month: Your estimated runtime pattern.
Electricity rate ($/kWh): Your utility’s rate per kilowatt-hour.

How it works

Estimate watts from BTU ÷ SEER.

Daily kWh = watts × hours ÷ 1000. Monthly = daily × days.

Cost = kWh × electricity rate.

Formula

Watts ≈ BTU ÷ SEER
kWh/day = (Watts × Hours) ÷ 1000
Cost = kWh × rate

When to use it

Estimating monthly AC operating cost.
Comparing units with different BTU and SEER ratings.
Budgeting for summer cooling or checking impact of increasing runtime.

Tips & cautions

Duty cycle varies with climate and thermostat settings; actual runtime may be lower than hours entered.
Use your actual $/kWh rate; time-of-use plans can change costs by time of day.
Simplified watt estimate from BTU/SEER; actual draw varies with temperature and cycling.
Does not factor in fan-only operation or variable-speed compressors precisely.

Worked examples

12k BTU, SEER 14, 8 hrs/day, $0.15/kWh

Daily kWh ≈ 6.9
Monthly kWh ≈ 207
Cost ≈ $31

24k BTU, SEER 16, 6 hrs/day, $0.20/kWh

Daily kWh ≈ 9
Monthly kWh ≈ 270
Cost ≈ $54

Deep dive

This AC cost calculator estimates daily/monthly energy use and cost from BTU, SEER, hours per day, and your electricity rate. Enter your usage pattern to see kWh and monthly dollars.

Use it to budget summer cooling, compare AC units, or understand how runtime changes affect your bill. Real-world duty cycles may differ—adjust hours to match your climate and habits.

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