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Electrical Calculators

Ohm's law, wattage, electricity cost, wire sizing, LED resistor, battery life.

πŸ“˜ When to use these

Electronics projects, home wiring, calculating electricity bills, or sizing components. From basic Ohm's law to practical wire sizing and LED circuits.

Enter any 2 values (leave the third empty)

VIR

Quick examples:

V
A

Quick examples:

W

Quick examples:

A

Quick examples:

V
V
mA

Resistor

500Ξ©

Power

200mW

πŸ“ Step-by-step breakdown:

R = (Vsupply - Vled) / Iled

= (12V - 2V) / 20mA

= 10V / 0.02A = 500Ξ©

Power = IΒ² Γ— R = 0.02Β² Γ— 500 = 200 mW

Use at least a ΒΌW resistor

Quick examples:

mAh
mA

Quick examples: