If you still have the original packaging or documentation that came with your PSU or your computer (if it was a pre-built system), the wattage might be listed there.
Input your CPU, GPU, and number of fans. It will recommend a wattage, which usually matches the "standard" build for those specs. how can i find out my psu wattage
Look for a large table printed on the PSU housing. If you still have the original packaging or
Here is the only reliable way to find your PSU wattage, along with a few workarounds if you can’t open your PC case. how can i find out my psu wattage