Calculator Inputs
Use the mode selector to solve for charge, current, time, electron count, or electrical energy. Voltage is optional unless energy or power is needed.
Plotly Graph
The chart updates after calculation. When current and time are available, it shows cumulative charge flow over time.
Example Data Table
| Case | Current (A) | Time (s) | Charge (C) | Voltage (V) | Energy (J) | Electrons Transferred |
|---|---|---|---|---|---|---|
| Battery Pulse | 0.50 | 20 | 10 | 9 | 90 | 6.24e19 |
| Motor Start | 4.00 | 15 | 60 | 24 | 1440 | 3.74e20 |
| Sensor Circuit | 25 mA | 300 | 7.5 | 5 | 37.5 | 4.68e19 |
| Capacitor Discharge | 1.20 | 8 | 9.6 | 18 | 172.8 | 5.99e19 |
| Bench Test | 2.50 | 60 | 150 | 12 | 1800 | 9.36e20 |
Formula Used
Q = I × t
Charge equals current multiplied by time. If 2 amperes flow for 5 seconds, the total transferred charge is 10 coulombs.
I = Q ÷ t
Current is the rate of charge flow. Divide transferred charge by elapsed time to find amperes.
t = Q ÷ I
Time can be found by dividing transferred charge by current. This is useful for discharge or charging duration estimates.
n = Q ÷ e
Electron count equals charge divided by the elementary charge, where e = 1.602176634 × 10-19 coulombs.
E = V × Q
Electrical energy in joules is voltage multiplied by transferred charge. When voltage is known, energy becomes easy to estimate.
How to Use This Calculator
- Choose the required calculation mode first.
- Enter the known values and select matching units.
- Add voltage if you want energy or power outputs.
- Press Calculate Now to view results above the form.
- Review the graph, summary cards, and example table.
- Use the CSV or PDF buttons to export your results.
FAQs
1. What is charge flow in physics?
Charge flow describes how electric charge moves through a conductor or circuit over time. Its rate is called current and is measured in amperes, which means coulombs per second.
2. What unit is used for electric charge?
The standard SI unit of electric charge is the coulomb. Practical electronics also use milliamp-hours and amp-hours, especially for batteries and storage devices.
3. How are charge and current related?
They are directly related by Q = I × t. A larger current or a longer time transfers more total charge through the circuit.
4. Why does the calculator include electron count?
Electron count helps connect circuit quantities to particle behavior. It shows how many electrons correspond to the transferred charge, which is useful in atomic and semiconductor discussions.
5. Can I use battery units like mAh?
Yes. The calculator accepts mAh and Ah for charge input. These units are converted internally into coulombs so the formulas stay consistent and correct.
6. What does the graph show?
When current and time are known, the graph plots cumulative charge against time. A straight line indicates constant current and a steady transfer rate.
7. How is energy connected to charge flow?
If voltage is known, energy follows E = V × Q. More charge passing through a higher potential difference produces more electrical energy in joules.
8. When should I use this calculator?
Use it for lab exercises, circuit analysis, battery estimates, classroom demonstrations, and quick engineering checks involving current, charge, duration, electrons, or energy.