Learn Electronics
The Hands-On Way

Interactive calculators and references for makers, hobbyists, and anyone curious about how circuits work.

9V RESISTORSHACK + 150Ω → LED Calculator

// Tools & References

// Quick Reference

Ohm's Law

V = I × R I = V / R R = V / I

Power

P = V × I P = I² × R P = V² / R

Series Resistors

Rtotal = R₁ + R₂ + R₃...

Parallel Resistors

1/Rt = 1/R₁ + 1/R₂...