Inductor Calculator Master

The complete offline coil toolkit. Air Core, Multi-Layer, Toroid & LC circuits. Target Solver, Correct My Coil, coil comparison — all on-device, no internet.

Inductor Calculator Master is the most complete offline coil calculator for electronics engineers, RF hobbyists, audio builders, and students who work with inductors every day.

No internet. No accounts. No guesswork. Enter your coil dimensions and get accurate results instantly — whether you are in the workshop, in the field, or somewhere with no signal at all.

WHAT YOU CAN CALCULATE

1. Air Core Solenoid Calculate inductance, wire length, and DC resistance for single-layer air-core coils. Supports both mm and inch units. Includes a coil diagram and practical winding tips from the electronics community.

2. Multi-Layer Coil Handle multi-layer windings using the correct multi-layer Wheeler formula. The app automatically warns you when your geometry would make a single-layer formula unreliable.

3. Toroid — Two Methods AL Value Method: enter the core's AL value and number of turns to get inductance. Physical Dimensions Method: enter outer diameter, inner diameter, height, and relative permeability to get inductance. Both methods output wire length and DC resistance.

4. LC Resonant Circuit Enter inductance and capacitance to get resonant frequency. Or enter target frequency and capacitance to find the required inductance. Instantly check whether your LC tank circuit hits the right frequency.

BUILT FOR REAL WORKFLOWS

1. Target Solver Know your target inductance? Enter it along with your coil geometry and the app tells you exactly how many turns to wind — no trial-and-error, no spreadsheets. Supports Air Core, Multi-Layer, Toroid AL, and Toroid Physical modes.

2. Correct My Coil Wound a coil that measures the wrong value on your LCR meter? Enter your measured inductance, your target inductance, and the current number of turns. The app calculates precisely how many whole turns to add or remove.

3. Compare 2 Designs Enter two Air Core configurations side by side and compare their inductance, wire length, and DC resistance in a single view. Faster than switching between tabs and recalculating manually.

4. Save to History Every calculation can be saved and recalled later. All inputs and outputs are preserved exactly as you entered them — no re-entering values across sessions.

EVERY RESULT INCLUDES

• Inductance displayed in auto-scaled units (H, mH, µH, or nH)
• Wire length required for the complete winding
• DC winding resistance
• Confidence rating (High, Medium, or Low) based on how well your geometry fits the formula's valid range
• Geometry-specific warnings when inputs fall outside ideal formula boundaries
• Real-world winding tips drawn from electronics community experience

100% OFFLINE

All calculations run entirely on your device. No data is ever sent to a server. The app works anywhere — workshop bench, shack, stockroom, or a metal building that kills your signal.

PRICING

• Free: All four main calculators (Air Core, Multi-Layer, Toroid, LC Resonant). Unlimited calculations, no time limits.
• Remove Ads — $0.99: Removes the banner ad from every screen. One-time purchase, no subscription.
• Premium — $1.99: Unlocks Quick Tools — Target Solver, Correct My Coil, and Compare 2 Designs. One-time purchase. Restore Purchases is fully supported.

WHO IT IS FOR

Amateur radio operators building tank circuits, filters, and matching networks. Audio engineers designing speaker crossover inductors. Power supply designers specifying filter chokes. Students studying electromagnetic induction and RF theory. Makers and hobbyists winding anything from custom sensors to coilgun stages.

If you wind wire around a form, this app belongs on your phone.