Clock Cycle Time Calculator
Determine how long each clock cycle lasts by entering the clock frequency in megahertz (MHz). The calculator instantly converts frequency into nanoseconds so you can size instruction timings, memory wait states, and digital circuit delays.
CalcSimpler Examples
- 1000 MHz ⇒ 1 ns per cycle
- 3200 MHz ⇒ 0.3125 ns per cycle
- 250 MHz ⇒ 4 ns per cycle
FAQ
Why does the formula use 1000 divided by the frequency?
One megahertz equals one million cycles per second. Converting seconds to nanoseconds adds a factor of 1,000,000,000, which simplifies to 1000 when frequency is expressed in MHz.
Can frequency be in GHz?
Yes. Multiply GHz by 1000 to convert to MHz, or enter the GHz value with three extra zeros (for example, 3.2 GHz becomes 3200 MHz).
What if frequency is zero?
A zero or negative frequency does not represent a valid clock, so the calculator shows no result. Enter a positive value to obtain a cycle time.
How precise is the result?
The computation assumes an ideal clock without jitter, skew, or propagation delays. Real hardware introduces small variations, so treat the output as a theoretical baseline.
Can I convert the answer to CPU instructions per second?
Yes. Once you know the cycle time, divide one second by that duration to see how many cycles occur in a second, and then multiply by the number of instructions executed per cycle.
Additional Information
- Cycle time is the reciprocal of frequency: cycle time (ns) = 1000 ÷ frequency (MHz).
- 1 GHz equals 1000 MHz, so a 1 GHz processor has a 1 ns cycle time.
- Divide the nanosecond result by 1,000,000,000 to convert it to seconds when estimating throughput per second.
- Accurate cycle timing helps with microcontroller interrupt budgeting, synchronous bus coordination, and FPGA design verification.
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