kW to BTU/hr Calculator
Use this quick tool to convert electrical power in kilowatts (kW) to heat output in BTU per hour (BTU/hr). Perfect for HVAC sizing, electric heater comparisons, and equipment planning.
Convert kW → BTU/hr
Formula: BTU/hr = kW × 3,412.142
Convert BTU/hr → kW
Formula: kW = BTU/hr ÷ 3,412.142
What Is the kW to BTU Conversion?
kW (kilowatts) and BTU/hr (British Thermal Units per hour) both describe power, but in different systems. Kilowatts are common in electrical and metric contexts, while BTU/hr is widely used in heating and air conditioning.
The core conversion factor is:
- 1 kW = 3,412.142 BTU/hr
- 1 BTU/hr = 0.000293071 kW
If you are comparing a heater, heat pump, furnace, or mini-split unit, this conversion helps you line up specs in a consistent way.
Quick Reference Table: kW to BTU/hr
| kW | BTU/hr | Typical Use Case |
|---|---|---|
| 0.5 | 1,706 | Very small electric heater |
| 1.0 | 3,412 | Portable appliance load |
| 1.5 | 5,118 | Small room heater |
| 2.0 | 6,824 | Medium electric heating load |
| 3.0 | 10,236 | Large room / workshop use |
| 3.5 | 11,942 | Common mini-split cooling class |
| 5.0 | 17,061 | Heavy residential load |
| 10.0 | 34,121 | Commercial-scale load |
How to Use This Calculator
For kW to BTU/hr
- Enter your power value in kilowatts.
- Choose the number of decimal places.
- Click Convert to see BTU/hr instantly.
For BTU/hr to kW
- Enter the thermal power in BTU per hour.
- Choose decimal precision.
- Click Convert to get the equivalent kW value.
Manual Formula (If You Want to Calculate by Hand)
You can always run the conversion manually with a basic calculator:
- BTU/hr = kW × 3,412.142
- kW = BTU/hr ÷ 3,412.142
Example: Convert 4.2 kW to BTU/hr:
4.2 × 3,412.142 = 14,331 BTU/hr (rounded)
Why This Matters for HVAC and Energy Planning
Many products list ratings in one unit only. You might see electric equipment rated in kW, while HVAC sizing charts use BTU/hr. Converting correctly helps you:
- Compare systems from different manufacturers
- Estimate required heating/cooling capacity
- Avoid under-sizing or over-sizing equipment
- Plan electrical demand with thermal output in mind
Common Mistakes to Avoid
- Confusing BTU and BTU/hr: BTU is energy; BTU/hr is power (rate).
- Ignoring context: Nameplate power input and delivered heating/cooling output are not always identical.
- Rounding too early: Keep extra decimals during planning, then round for presentation.
- Skipping efficiency/COP: Heat pumps can deliver more thermal output than electrical input due to coefficient of performance.
Frequently Asked Questions
Is 12,000 BTU/hr equal to 1 ton?
Yes. In HVAC, 1 ton of cooling capacity equals 12,000 BTU/hr.
How many BTU/hr is 1.5 kW?
1.5 × 3,412.142 = 5,118.21 BTU/hr.
Can I use this for electric heaters and AC units?
Yes. The unit conversion itself is universal for power. Just remember that real system performance may also depend on efficiency, operating conditions, and equipment type.
Bottom Line
If you need a fast and accurate kW to BTU conversion, this calculator gives you both directions in seconds. Use it for HVAC sizing checks, appliance comparisons, and everyday engineering estimates.