Vol. IV — Electronics · Tool
Four bands, base unit µH: two digits, a multiplier, then optional tolerance. Click a band or a swatch. Type a value to snap to a nearby E12 hobbyist inductance.
Nearest E12 4-band match shown above. Common hobbyist inductor series.
Band 1 and band 2 are digits (same colors as resistors). Band 3 multiplies them in µH per EIA / IEC 61605 — black ×1, brown ×10, red ×100, … gold ×0.1, silver ×0.01; violet ×0.001 and gray ×0.0001 cover the tiny end. Band 4 is tolerance: gold ±5%, silver ±10%, brown ±1%, red ±2%, or no band ±20%.
Example: yellow · violet · black · gold → 47 × 1 = 47 µH ±5%. Lookup snaps to the E12 series (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82) — the common hobbyist decade set for axial inductors.
Pair with Resistor codes, Capacitor codes, RL time, or Reactance once you know L.