Buck Boost Duty Cycle Calculator
Calculate ideal buck, boost or inverting buck-boost duty cycle and inductor-current ripple, with a continuous-conduction validity check.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Apply ideal CCM voltage ratios and inductor volt-second balance, then reject inputs whose triangular current reaches zero.
Buck D=Vo/Vi; boost D=1−Vi/Vo; inverting D=|Vo|/(Vi+|Vo|)
Worked example
An ideal 12 V to 5 V buck with 10 Ω load, 100 μH and 100 kHz has duty 41.6667%, output current 0.5 A and inductor ripple about 0.291667 A peak to peak.
Assumptions and input details
Ideal steady-state continuous conduction only; a positive minimum inductor current is required. Inverting output is negative but entered as a positive magnitude. No efficiency assumption beyond ideal power conservation is added. Semiconductor drops, losses, output ripple, transient control, component selection and electrical ratings are excluded. This is numerical analysis, not a build-ready circuit design.
References: TI: buck, boost and inverting inductor-current relationships · Analog Devices: inverting buck-boost topology
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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