Resistor Calculator (Series and Parallel)
Find the equivalent resistance of resistors in series or parallel. The result updates as you type, with the working underneath so you can check it.
Your details
Result
Equivalent resistance
56.8966 Ω
- 3 resistors.
Good to know: Series: R = ΣRᵢ · Parallel: 1/R = Σ1/Rᵢ
Please note: For study and planning. Check calculations independently before using results with chemicals, electricity, pressure or machinery, and follow safety data sheets, manufacturer instructions and local regulations.
About this tool
Formula
Series: R = ΣRᵢ · Parallel: 1/R = Σ1/Rᵢ
Questions people ask
Why is parallel resistance lower?
Each extra path gives current more room to flow, so the combined resistance is below the smallest single resistor.
Related tools
- Ohm's Law CalculatorSolve for voltage, current or resistance, with power.
- Electrical Power CalculatorCalculate power in watts from voltage and current, with kWh per hour.
- Electricity Cost CalculatorWork out what an appliance costs to run from its wattage and your tariff.
- Kinetic Energy CalculatorCalculate the kinetic energy of a moving object from its mass and speed.
How we calculate this
We use the standard published formula or definition for this calculation, and we show the working so you can check it.
Spotted a mistake? Tell us and we'll check it. How we check our calculators