Electric Charge Calculator
Enter a current and a time to get the electric charge in coulombs — plus the equivalent number of electrons — using the simple Q = I × t relationship.
Charge and electrons at once
Enter the current and time and the electric charge calculator returns the charge (I × t) in coulombs and the equivalent number of electrons together.
Use SI units
Current in amperes and time in seconds give charge in coulombs — convert minutes by ×60 and hours by ×3600 to seconds before you start.
What is electric charge?
The amount of electricity that flows
The electric charge calculator turns a current and a time into the charge that flows through a circuit. Electric charge is the amount of electricity that passes a point, measured in coulombs (C): one coulomb is a steady current of one ampere flowing for one second. From two everyday measurements — the current in amperes and the time in seconds — it returns the charge in coulombs alongside the number of electrons that charge represents. It is the number behind how much a battery delivers, how long a capacitor takes to fill, and how much electricity moves through a wire.
Enter a current in amperes and a time in seconds to get the electric charge in coulombs and the matching electron count instantly.
Electric charge is the current multiplied by the time it flows, and the electron count is that charge divided by the elementary charge.
Q = I × tCharge grows in direct proportion to both inputs: double the current or double the time and you double the charge. To express the same result as a number of electrons, divide the charge by the elementary charge, e = 1.602176634 × 10⁻¹⁹ C — the charge on a single electron. Use amperes and seconds and the charge comes back in coulombs.
Suppose a steady current of 2 A flows for 10 seconds.
Multiply current by time
2 × 10 = 20 — current in amperes times time in seconds.
Read the charge
The electric charge is 20 coulombs (C) — that is the result.
Convert to electrons
20 ÷ 1.602176634 × 10⁻¹⁹ ≈ 1.2483 × 10²⁰ electrons flow past the point.
The two outputs describe the same flow in different ways. The charge in coulombs (20 C for the example above) is the practical figure used in electronics — it tells you how much electricity has moved, and it is what sizes batteries (often quoted in amp-hours, which are just coulombs ÷ 3600) and what fills a capacitor to a given voltage. The electron count (about 1.2483 × 10²⁰) is the same charge expressed as individual particles, which makes vivid just how many electrons move even in a brief, modest current. Because charge is simply current times time, the two inputs trade off cleanly: a small current over a long time can move the same charge as a large current over a short time. That is why a trickle charger and a fast charger can both fully charge the same battery — they deliver the same total charge, just at different rates.
The formula is exact, but a couple of practical points are worth keeping in mind.
Steady current and consistent units
This calculator assumes a constant (steady) current over the whole time. If the current varies, Q = I × t uses only the average current, and the true charge is the area under the current–time curve. Keep your units consistent — amperes for current and seconds for time — or the coulombs will be wrong: convert minutes by multiplying by 60 and hours by 3600 before you enter the time.