🇬🇧 EN🇫🇷 FR 🇪🇸 ES 🇧🇷 PT 🇩🇪 DE 🇮🇹 IT 🇳🇱 NL 🇸🇪 SV 🇳🇴 NO 🇫🇮 FI 🇵🇱 PL 🇹🇷 TR 🇷🇺 RU

🔒 100% Local — No data sent⚡ No signup needed🛡️ Nothing stored

Ohm's Law Calculator

Enter any two values to calculate the other two instantly.

Voltage (V)

Current (A)

Resistance (Ω)

Power (W)

Enter any 2 of the 4 values above

🔋

Enter any 2 of the 4 values above

Key Formulas

V = I × R

I = V / R

R = V / I

P = V × I

P = I² × R

P = V² / R

Look up resistor color bands with our resistor calculator, size your conductors using the wire calculator, or find the right resistor for your LEDs with the LED calculator.

You might also need:

Electricity Cost Calculator

Running cost of any appliance per day, month & year. 12 presets.

Wire Size Calculator

AWG gauge by current, distance & voltage drop. Cu/Al.

LED Resistor Calculator

Current-limiting resistor with E24 value & color code bands.

Resistor Color Code

Decode/encode 4 and 5 band resistors. Visual preview.

🔧 115+ tools