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Buck Converter Calculator
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Calculate output voltage and duty cycle for a DC-to-DC step-down converter.
Input Parameters
Solve Duty Cycle
Solve Vout
Input Voltage (Vin)
V
Output Voltage (Vout)
V
Efficiency (η)
%
Reset
Calculation Results
Required Duty Cycle (D)
-
Duty Cycle (%)
-
%
Voltage Reduction
2.40
x
About this calculator
Quick Reference
Vin
Input Voltage
Vout
Output Voltage
D
Duty Cycle (fraction of period switch is on)
η
Efficiency
Overview
A buck converter (step-down converter) is a DC-to-DC power converter which steps down voltage from its input to its output.
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Pro Tips
Duty cycle (D) must be between 0 and 1.
Efficiency defaults to 100% in simplified calculations, but real converters are usually 85-95%.
Vout must be less than Vin for a buck converter to function.
!
Fun Facts
"Buck converters are found in computer motherboards to step down 12V to the ~1.2V needed by the CPU."
"They are highly efficient compared to linear regulators because they don't dissipate excess voltage as heat."
"The term 'Buck' refers to bucking or opposing the voltage."
Formula: Vout = Vin * D
