How to use the rc discharge time calculator
Find how long a capacitor takes to discharge down to a threshold voltage. Enter starting voltage, threshold voltage, resistance, capacitance in the fields above; the time to reach threshold, time in minutes are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “capacitor discharge time”, “RC time to drop voltage”, “discharge to threshold”, “calculate rc discharge time”, “find time to reach threshold”.
Formula
Variables
- V0 — Starting voltage (V)
- Vth — Threshold voltage (V)
- R — Resistance (kΩ)
- C — Capacitance (µF)
Worked example
With starting voltage = 5 V, threshold voltage = 1 V, resistance = 10 kΩ, capacitance = 100 µF, the calculator gives time to reach threshold ≈ 1.609438 s; time in minutes ≈ 0.02682397 min.
Frequently asked questions
What is the rc discharge time calculator used for?
Find how long a capacitor takes to discharge down to a threshold voltage. It helps with questions such as “capacitor discharge time”, “RC time to drop voltage”, “discharge to threshold”.
What is the formula for the rc discharge time calculation?
Time to reach threshold (s) = R × 1000 × C × 1e-6 × ln(V0 / Vth). Time in minutes (min) = [Time to reach threshold] / 60. Here V0 is starting voltage (V), Vth is threshold voltage (V), R is resistance (kΩ), C is capacitance (µF).
What inputs do I need for the rc discharge time calculator?
You need starting voltage in V, threshold voltage in V, resistance in kΩ, capacitance in µF. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the rc discharge time calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the rc discharge time result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.