How to Calculate Power Calculator
What is Power Calculator?
A power calculator computes electrical power (watts), and can find any unknown from P=VI, P=I²R, or P=V²/R. Also converts between watts, kilowatts, horsepower, and BTU/hr.
Formula
Power = base^exponent; bⁿ = b × b × b... (n times); b⁰ = 1; b⁻ⁿ = 1/bⁿ
- b
- Base (number)
- n
- Exponent (count)
- P
- Result (value)
Step-by-Step Guide
- 1P = V × I (Power = Voltage × Current)
- 2P = I² × R (using current and resistance)
- 3P = V² / R (using voltage and resistance)
- 41 kW = 1,000 W; 1 HP = 745.7 W; 1 BTU/hr = 0.293 W
Worked Examples
Input
Kettle: 230V, 10A
Result
P = 230 × 10 = 2,300W = 2.3 kW
Frequently Asked Questions
What does 2^10 equal?
2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 = 1024.
How do negative exponents work?
2⁻³ = 1/2³ = 1/8 = 0.125. Negative exponent = reciprocal.
What's the difference between 2^3 and 3^2?
2³ = 8 (2 × 2 × 2). 3² = 9 (3 × 3). Order matters.