General:
* Size
* Extent
* Scale
* Importance
* Significance
* Weight
* Intensity
* Volume
Specific:
* Strength (for force)
* Brightness (for light)
* Amplitude (for waves)
* Volume (for sound)
* Quantity (for numbers)
* Amount (for quantities)
* Degree (for intensity)
Examples:
* The magnitude of the earthquake was devastating. (You could replace "magnitude" with intensity or strength.)
* The magnitude of her success is remarkable. (You could replace "magnitude" with scale or extent.)
* The magnitude of the problem is overwhelming. (You could replace "magnitude" with importance or significance.)
Choose the best word based on the specific meaning you want to convey.