BTU to kW/kWh Calculator

BTU to kW Conversion

Understanding the relationship between BTU and kW helps compare AC specifications and calculate electricity costs. These unit conversions are fundamental to HVAC calculations.

Conversion Formulas

The key conversion factors:

• 1 kW = 3,412 BTU/hour
• 1 BTU/hour = 0.000293 kW
• 1 ton = 12,000 BTU = 3.517 kW

BTU to kW Conversion

To convert cooling capacity (BTU) to power (kW):

• Formula: kW = BTU ÷ 3,412
• 9,000 BTU: 2.64 kW (0.75 ton)
• 12,000 BTU: 3.52 kW (1 ton)
• 18,000 BTU: 5.28 kW (1.5 ton)
• 24,000 BTU: 7.03 kW (2 ton)

kW vs kWh Explained

These terms are often confused but represent different things:

• kW (kilowatt): Power — the rate of energy use at any moment
• kWh (kilowatt-hour): Energy — total power consumed over time
• Relationship: kWh = kW × hours
• Analogy: kW is like speed; kWh is like distance traveled

Practical Examples

• AC rated at 1.5 kW running 8 hours: 1.5 × 8 = 12 kWh used
• Electricity cost: 12 kWh × $0.12/kWh = $1.44
• Monthly usage: 12 kWh × 30 days = 360 kWh = $43.20

Important Note About AC Power

AC nameplate ratings can be confusing:

• Cooling capacity (BTU): Heat removed from room per hour
• Power consumption (kW): Electricity used by the unit
• They are not equal: A 12,000 BTU (3.52 kW cooling) AC typically consumes only 1-1.5 kW of electricity
• This difference is EER: Energy Efficiency Ratio = BTU ÷ Watts consumed

Quick Reference Table

• 0.75 ton: 9,000 BTU, ~0.8-1.0 kW consumption
• 1.0 ton: 12,000 BTU, ~1.0-1.3 kW consumption
• 1.5 ton: 18,000 BTU, ~1.5-2.0 kW consumption
• 2.0 ton: 24,000 BTU, ~2.0-2.5 kW consumption