How do you calculate Boost Inductor Value?

Use the formula L = Vin × (Vout − Vin) / (ΔIL × fs × Vout). This sizes the inductor of a boost (step-up) converter for a target peak-to-peak ripple current. Enter the values you know in the calculator above and it solves for the remaining variable.

What is the formula for Boost Inductor Value?

The Boost Inductor Value formula is L = Vin × (Vout − Vin) / (ΔIL × fs × Vout), where L—Inductance (H); Vin—Input voltage (V); Vout—Output voltage (V); ΔIL—Target peak-to-peak ripple current (A); fs—Switching frequency (Hz).

Boost Inductor Value

L = Vin·(Vout−Vin) / (ΔIL·fs·Vout)

Calculator

Inductance

Input Voltage

Output Voltage

Ripple Current

Switching Frequency

Result

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Formula

L = Vin × (Vout − Vin) / (ΔIL × fs × Vout)

Description

This sizes the inductor of a boost (step-up) converter for a target peak-to-peak ripple current. The ripple is set by the volt-seconds applied to the inductor during the switch on-time, which depends on the input/output voltage ratio and the switching frequency. A larger inductor or higher frequency reduces ripple at the cost of size or switching loss.

Variables

L — Inductance (H)
Vin — Input voltage (V)
Vout — Output voltage (V)
ΔIL — Target peak-to-peak ripple current (A)
fs — Switching frequency (Hz)

Practical Notes

A common design target is ΔIL ≈ 20–40% of the average inductor current. The inductor must not saturate at the peak current Iout/(1−D) + ΔIL/2.

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