Does this apply to discharge as well?
Yes. RC discharge follows the same time constant; the milestones tell you when voltage decays to 37%, 5%, and 1%.
Step-by-step walkthrough
RC Time Constant Guide
Use this companion guide beside the interactive calculator to make sure you understand the “why” behind every click. Each section includes the classroom explanation, student-friendly language, and quick practice prompts.
Before you start
Collect the data points listed below and double-check their units. Keeping an organized “givens” list is one of the fastest ways to reduce math errors and impress exam graders.
- rc circuit
- time constant
- tau
Detailed procedure
Step 1
Select the units for R (Ω, kΩ, MΩ) and C (F → nF).
Step 2
Enter the numeric values for resistor and capacitor.
Step 3
Read τ in seconds plus the time to reach 63%, 95%, and 99% of the final voltage.
Teaching & troubleshooting tips
Can I include load resistance?
The base formula assumes a single resistor. Combine equivalent resistances first, then plug the result into the calculator.