Instant LC Resonant Frequency Online – Perfect for Antennas, Filters & Oscillators

10/06/2025

Free LC Circuit Resonant Frequency Calculator – RF & Electronics Made Easy!

Why use it?

• No math needed – just enter the values of the inductor (L) and capacitor (C).
• The calculator instantly provides the resonant frequency in Hertz (Hz).
• Useful for RF design, filter tuning, oscillators, antennas, and educational labs.
• Available anytime online – 100% free and user-friendly.

Practical Applications:

1. RF Engineering: Quickly design radio receivers or transmitters by calculating the resonance point of LC filters.
2. Antenna Tuning: Find the optimal operating frequency for antennas in wireless communication projects.
3. Oscillators & Signal Generators: Ensure your circuit oscillates at the desired frequency in MHz or GHz ranges.
4. Student Projects: Perfect tool for lab classes – instant results for assignments or experiments.

Student Project 1 — FM Radio (100 MHz)

Task: select a capacitor for an LC tuner circuit at 100 MHz.
Solution using the calculator:

1. Click on C (calculate C).
2. Enter L = 0.25 µH.
3. Enter f = 100 MHz.
4. Click Calculate → result:
   C ≈ 10.13 pF.

Note: it’s convenient to use a variable capacitor around 5–15 pF for fine tuning the station.

Practical Project 2 — Wi-Fi Antenna Tuning (2.4 GHz)

Task: select inductance for a matching LC network at 2.4 GHz with a chosen small SMD capacitor.
Solution using the calculator:

1. Click on L (calculate L).
2. Enter C = 2.2 pF.
3. Enter f = 2.4 GHz.
4. Click Calculate → result:
   L ≈ 2.00 nH.

Alternative: with C = 1.0 pF, the result is L ≈ 4.40 nH, which is practical if you have standard inductors of 4.3–4.7 nH.

Practical tips:

• At gigahertz frequencies, watch out for parasitic L and C of PCB traces; keep connections short with a ground plane.
• Fine-tuning is done by adjusting capacitance ±0.2–0.5 pF or slightly trimming the trace length.

Electronics doesn’t have to be complicated – with our LC Circuit Resonant Frequency Calculator, you can focus on building and testing, while the math is done for you. Try it today on tmatlantic.com, and discover over 40 more free online calculators for engineers and students.