This calculator converts the ratio of Frequency variation to Center frequency (Hz/kHz/MHz/GHz) to parts per million (PPM)

**Formula**

**ppm** = **(df/F)*10 ^{6}**

where

**F**is the center frequency**df**is the peak frequency variation**ppm**is the resulting parts per million

## Example

At a frequency of 1 GHz if the system is specified for a peak frequency shift of 100 Hz, then the reference oscillator has to be better than +/- 0.1 ppm.