The formula
3/4-digit: value = (leading digits) × 10^(last digit) ; EIA-96: value = lookup(2 digits) × letter multiplier
- 3-digit
- two significant figures plus a multiplier, e.g. 473
- 4-digit
- three significant figures plus a multiplier, e.g. 4702
- R
- marks a decimal point, e.g. 4R7 = 4.7 Ω
- EIA-96
- two digits index a standard table, a letter gives the multiplier
Worked example
Markings 473, 4702 and 01C.
- 473 = 47 × 10³ = 47 kΩ
- 4702 = 470 × 10² = 47 kΩ (same value, tighter tolerance series)
- 01C: code 01 → 100, letter C → ×100, so 100 × 100 = 10 kΩ
47 kΩ, 47 kΩ and 10 kΩ respectively.
Where you'll use it
Repair and board bring-up, where you need a part's value and the board has no silkscreen. A part marked 000 or 0 is a zero-ohm link — a wire jumper in resistor packaging.