Case 1
- Steady current
- 2A
- How long it flows
- 10s
20.000000C
Open with these valuesElectric Charge Calculator
Change any value to update the result.
20.000000C
Charge: 20.000000 CExamples
Charge is simply current times time: Q = I × t. One ampere flowing for one second delivers one coulomb, so 2 A for 10 seconds is 20 C. Enter the current in amperes and the time in seconds — an hour is 3600, not 1.
The numbers at a glance
Held fixed: Steady current 2.000000 A.
| How long it flows (s) | Charge (C) |
|---|---|
| 0.000 | 0.000000 |
| 2.500 | 5.000000 |
| 5.000 | 10.000000 |
| 7.500 | 15.000000 |
| 10.000Your value | 20.000000 |
| 12.500 | 25.000000 |
| 15.000 | 30.000000 |
| 17.500 | 35.000000 |
| 20.000 | 40.000000 |
Worked examples
Case 2
- Steady current
- 0.001A
- How long it flows
- 3600s
3.600000C
Open with these valuesCase 3
- Steady current
- 0.5A
- How long it flows
- 60s
30.000000C
Open with these valuesHow it's calculated
Q = I × t
- StepEnter the current in amperes — 1 mA is 0.001, not 1.Steady current=2A
- StepEnter the time in seconds: minutes × 60, hours × 3600.
- ResultRead the charge in coulombs, one coulomb per ampere-second.20.000000C
Reference table
| Current, time | What it is | Charge |
|---|---|---|
| 0.001, 3600 | One milliamp for a whole hour | 3.6 |
| 0.5, 60 | Half an amp for a minute | 30 |
| 1, 1 | The definition of the coulomb itself | 1 |
| 2, 10 | A phone charger for ten seconds | 20 |
| 3, 5 | Three amps for five seconds | 15 |
Questions
How do I calculate electric charge?
Multiply the current by the time it flows: Q = I × t. Amperes and seconds give the charge in coulombs, so a 2 A current for 10 seconds delivers 20 coulombs.
What is a coulomb?
It is the SI unit of electric charge, defined as the charge carried by a steady current of one ampere in one second. That makes one coulomb the same thing as one ampere-second.
How many electrons is that?
One coulomb is about 6.241509 × 10¹⁸ electrons, because each electron carries the elementary charge e = 1.602176634 × 10⁻¹⁹ C. Divide the charge by e to get the electron count.
My time is in minutes or hours — what do I enter?
Convert it to seconds first: multiply minutes by 60 and hours by 3600. One milliamp for an hour is 0.001 × 3600 = 3.6 coulombs, not 0.001.
Does this work for a changing current?
No. The formula assumes a steady current for the whole period. For a current that varies you need the area under its curve over time, which this calculator does not do.