3 kΩ in E12: this page
- Input
- target 3k E12
- Expected output
- 1.2k + 1.8k
Exact sum of 3,000 Ω.
Carregando ferramenta… / Loading tool…
how to make a 3k resistor from standard values
The 3 kΩ is missing from the box. The E12 series, the most common in stores, goes from 2.7 kΩ straight to 3.3 kΩ, and neither will do if the circuit asks for 3 kΩ. The fix is to combine two resistors that exist. The tool opens on the Reach a value tab with 3 kΩ, E12 and two resistors at most, and lists the combinations from smallest error to largest.
Exact sum of 3,000 Ω.
Two equal ones in series.
Two 100 Ω in parallel.
Two 150 Ω in parallel.
Exact sum, with no 4.9 kΩ in the series.
124.7 Ω, an error of −0.24%.
Add the inverses and invert the result: R = 1 ÷ (1 ÷ R1 + 1 ÷ R2 + ...). For two, R = R1 × R2 ÷ (R1 + R2). Example: 220 Ω and 330 Ω give 132 Ω. The result is always smaller than the smallest resistor.
In series, 1.2 kΩ + 1.8 kΩ or 1.5 kΩ + 1.5 kΩ, which sum to exactly 3 kΩ. Or 3.3 kΩ in parallel with 33 kΩ. If you have the E24 series, 3 kΩ exists as a single part.
Because it has only 12 values per decade, spaced about 21% apart. E12 jumps from 2.7 kΩ to 3.3 kΩ. E24, with 24 values, includes 3.0 kΩ.
Series for values larger than each part, parallel for values smaller. If the target is 3 kΩ and you have 1.5 kΩ, use series. If the target is 50 Ω and you have 100 Ω, use parallel.
No. Each part's tolerance adds to the error. Two 5% resistors in series give a total with up to about 5% deviation. For accuracy, use a single 1% part.
Yes: the 3-resistor option tests series, parallels and both mixed forms. It finds closer combinations when two parts are not enough, at the cost of a bigger circuit.
The list runs from smallest error to largest and, on a tie, prefers fewer resistors. Series sums and parallel (∥) use nominal values from the chosen series.
The math runs in your browser; no value is sent to a server. Combinations use nominal values: resistor tolerance adds on top of the error shown.