RC Time Constant Calculator
How fast does a capacitor charge through a resistor?
One time constant (R × C) charges a capacitor to about 63%. Everything is worked out in your browser. Nothing is saved or sent anywhere.
1. Parts
2. Check a time
3. Results
How it was worked out
What this does and doesn't tell you
- Discharging follows the same curve in reverse: down to about 37% after one time constant.
- 240V AC mains can kill. In Australia, work on household mains wiring must be carried out by a licensed electrician. Low-voltage DC systems can still deliver very high current.