Widerstandsrechner

Decode resistor color codes, calculate series and parallel resistance, and find power dissipation. Free, fast, and easy to use.

Berechnen

Choose a calculation type, enter your values or select color bands, and click Calculate Now to get instant results with step-by-step solutions.

Vollständiges Benutzerhandbuch

Was ist ein Widerstand?

A resistor is an electrical component that limits or controls the flow of electric current in a circuit. Resistance is measured in ohms (Ω) and is usually shown by colored bands on the resistor body. This tool helps you decode those color bands, combine resistors in series or parallel, and calculate power dissipation — all for free.

All Formulas at a Glance

Farbcode: R = (digits) × multiplier ± tolerance%

Serie: R_total = R1 + R2 + R3 + …

Parallel: 1/R_total = 1/R1 + 1/R2 + 1/R3 + …

Leistung: P = V² / R  |  I = V / R

4 Calculation Types

Farbcode

Dekodieren Sie den Widerstand anhand von 4-Band-, 5-Band- oder 6-Band-Farbcodes auf einem Widerstand.

Serienwiderstand

Calculate total resistance when resistors are connected end to end.

Paralleler Widerstand

Calculate total resistance when resistors are connected side by side.

Verlustleistung

Finden Sie anhand von Spannung und Widerstand heraus, wie viel Leistung ein Widerstand verbraucht.

So verwenden Sie diesen Rechner

  1. Wählen Sie aus, was Sie berechnen möchten – Farbcode, Serie, Parallel oder Leistung.
  2. Enter resistor values or select color bands.
  3. Wählen Sie bei Bedarf Einheiten (Ohm, Kiloohm, Megaohm).
  4. Click Calculate Now and see your answer with a step-by-step breakdown and chart.

Resistor Color Code Chart

• Black=0, Brown=1, Red=2, Orange=3, Yellow=4

• Green=5, Blue=6, Violet=7, Gray=8, White=9

• Gold multiplier = ×0.1, Silver multiplier = ×0.01

• Toleranz: Braun ±1 % %, Rot ±2 % %, Gold ±5 % %, Silber ±10 % %

Quick Examples

• Braun-Schwarz-Rot-Gold = 10 × 100 = 1000 Ω (1 kΩ) ±5 %

• Zwei 100-Ω-Widerstände in Reihe = 200 Ω

• Zwei 100 Ω-Widerstände parallel = 50 Ω

• 12 V an 100 Ω = 1,44 W Verlustleistung

Wichtige Hinweise

  • All resistance values must be greater than zero.
  • Color bands are read from left to right — the tolerance band is usually gold or silver.
  • Unit conversions are done automatically — just pick your preferred unit.
  • At least two resistors are needed for series and parallel calculations.

📤 Share This Tool