Example 1
Q = 10 C, t = 5 s → I = 2 A.
Current Calculator
Type charge Q [C] and time t [s]. The calculator computes I = Q/t: 10 C in 5 s is 2 A, and 3600 C in 3600 s is 1 A. t = 0 does not divide.
Inverse: Q = I·t. Power: P = U·I.
Result
Charge Q (C) and Time t (s). The result shows up here.
How it works
Average current from charge and time is I = Q/t. At 10 C in 5 s you get 2 A. At 3600 C in one hour (3600 s) you get 1 A. At 0.5 C in 0.25 s you get 2 A again. That is average I over the interval, not a scope spike.
The form has two fields: Q in coulombs and t in seconds. The result is in amperes. An hour is 3600, not 1. A comma and a period mean the same Q: 0,5 and 0.5. 1 Ah = 3600 C, so 3600 C / 3600 s = 1 A.
t must be positive, because you do not divide by zero. Typed 0 in t is rejected. Zero coulombs at positive t gives I = 0. Both fields need a number before 2 A appears.
Q = I t is on the neighbouring page: same pair, you solve for charge. P = U I computes power from voltage, not I from coulombs. I = P/U is yet another calculator when you know watts and volts.
A negative Q is charge sign and gives negative I. This calculator does not model a waveform pulse. It takes steady Q and t.
Type 10 and 5, click Calculate, and check 2 A. Then 3600 and 3600: 1 A. The calculator divides Q by t; it does not guess the current shape.
How to use
- In the first field enter Q in coulombs, for example 10. 1 Ah is 3600 C.
- In the second field enter t in seconds, for example 5. One hour is 3600, not 1.
- Click Calculate. 10 C and 5 s give 2 A. 3600 C and 3600 s give 1 A.
- t = 0 is rejected. Zero in Q at positive t gives I = 0. Both fields need a number.
- For Q = I t, open charge. Power P = U I is a different page.
Formula
I = Q / t
SI units: A, C, s. Time t must be positive.
I from charge and time
The inverse of Q = I t: here I = Q/t. 10 C in 5 s is 2 A. 3600 C in 3600 s is 1 A. t must be positive.
- I
- Current [A]. 10 / 5 = 2 A. Average current on interval t.
- Q
- Charge that flowed [C]. 3600 C in an hour is 1 A.
- t
- Time [s]. t = 0 does not divide. Not the rotation period T.
Real-life examples
Example 2
1 Ah in one hour → I = 1 A.
Example 3
Short pulse: I = 2 A.
Example 4
Q = 120 C, t = 60 s → I = 2 A.
Example 5
Fast charge → I = 1000 A.
Example 6
Q = 50 C, t = 10 s → I = 5 A.
Example 7
Small charge, short time: I = 2 A.
Example 8
2 Ah in two hours → I = 1 A.
Example 9
Slow flow: I = 0.1 A.
Example 10
Q = 100 C, t = 20 s → I = 5 A.
Ways to use this calculator
- You compute 2 A from 10 C in 5 s.
- You check 1 Ah in one hour: 1 A.
Frequently asked questions
How much I at 10 C and 5 s?
Current is 2 A. You divide 10 C by 5 s. That is the average current on this interval, not I = P/U.
How much at 3600 C and 3600 s?
You get 1 A. That is 1 Ah spread over an hour: 3600 C in 3600 s.
Which units do I type?
Charge Q [C], time t [s]. Result I [A]. An hour is 3600 s, not a 1 in field t.
How is this different from Q = I t?
Here you solve I = Q/t. There you multiply I by t and get charge. The inverse of the same pair.
Is this instantaneous current?
No. This is average I on interval t. Instantaneous i(t) needs the derivative of Q, which this calculator does not compute.
Does a comma in 0.5 C work?
Yes. 0.5 and 0,5 are the same Q [C]. 0.5 C in 0.25 s is also 2 A.
Where is P = U I?
On the electric-power page. There watts from volts and amperes. Here I comes from charge and time.
Is 1 Ah 3600 C?
Yes. 1 A for 3600 s is 3600 C. That is why 3600 C in an hour gives 1 A.
What about t = 0?
The calculator refuses zero seconds. I = Q/t at zero time does not exist.
How much at 0.5 C and 0.25 s?
Current is 2 A. The same I as 10 C in 5 s, only on a shorter interval.
Knowledge sources
The formula is the school one. Units follow SI; NIST SP 330 and BIPM define the measures, not your result.
Page updated in 2026.