アンペアから ワット 計算機
アンペア値と入力電圧を入力するだけで、デバイスが使用するワット数を素早く把握できます。小型家電の効率測定に不可欠です。
消費電力計算機
アンペア → ワット
負荷が使用する有効電力の測定値。
変換式
電力計算は回路の種類によって異なります — すべてのACシステムには力率が必要です。
直流システム
W = I × V 基本の電力方程式 — すべての直流回路においてアンペア×ボルトはワットに等しくなります。
単相AC
W = I × V × PF 力率は電圧と電流の位相差を考慮し、実効有効電力を低下させます。
三相AC
W = √3 × I × V × PF 平衡三相電力は3つの相すべてで合算され、線間電圧には√3(1.732)の係数が使われます。
How to Convert Amps to Watts
Converting amperes to watts tells you how much real power a device consumes. This is essential for calculating energy costs, sizing generators, verifying circuit capacity, and comparing appliances. Multiply amps by volts — then apply the power factor for AC systems.
Real Power vs. Apparent Power
Real power (watts) is energy that actually does work — turning a motor, heating an element. Apparent power (VA) is what the supply delivers including reactive current. For heaters and lamps they're equal. For motors and transformers, watts are always lower than VA because some current builds magnetic fields without doing useful work.
Practical Applications
- Energy Cost Calculation: Convert amps to watts, multiply by hours of use to get Wh, divide by 1000 for kWh, then multiply by your electricity tariff.
- Generator Sizing: Sum the watts of all simultaneous loads and add 25% for motor startup surges.
- Circuit Load Audit: Sum all load watts on a circuit. The total should not exceed 80% of the breaker rating × voltage (NEC continuous load rule).
Step-by-Step Conversion
- Read the Current: Measure with a clamp meter or find the amp rating on the device nameplate.
- Note the Voltage: Check your supply — 120V or 240V in North America; 230V in most of Europe.
- Apply Power Factor: Use 1.0 for pure resistive loads. Use 0.8–0.9 for motors and inductive equipment.
- Multiply: I × V for DC; I × V × PF for single-phase AC; √3 × I × V × PF for three-phase AC.