Electrical calculators
Works in your browser. Nothing is uploaded.Resistor color code
Pick the colors of a resistor’s bands to read its value, or type a value to see its bands.
Resistance
4.7 kΩ±5%
Ω
Electrical calculators
Resistor color codeBands to ohms and back.Ohm’s law and powerVolts, amps, ohms and wattsVoltage drop and cable sizeThe drop over a run, and the smallest cable within itWire sizesAWG, mm², kcmil and diameterLED resistorThe resistor an LED needsSMD codesResistor and capacitor markings555 timerAstable and monostableBattery runtimeHow long a battery lasts
How to use it
- Count the bands
Hold the resistor with the gold or silver band on the right, then pick 4, 5 or 6 bands.
- Pick each color
From the left. The drawing and the value follow.
- Or type a value
Type 4.7k, 220 or 1M to see which colors to look for.
Tips
- Which end first
Gold and silver are never first. Start from the end with the band closest to the edge.
- Brown or red?
In poor light brown, red and orange look alike: check with a meter when it matters.
- Five bands
Precision resistors use three digits, so 4.7 kΩ reads yellow, violet, black, brown.
In the app
Electrical calculator in Angle Meter
- Ohm’s law, AC power and voltage drop
- Wire sizes, motors and loop impedance
- LED, 555, coils, antennas and speaker boxes
- Wire colors, plugs, IP and NEMA references
Get it onGoogle PlayComing soon to the App Store
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