The go-to chart for determining which width tires will fit a particular rim can be found at the late Sheldon Brown's website
https://www.sheldonbrown.com/tire-sizing.html. Scroll down until you see the chart in red and green. This tells you which tire widths are safe with your existing rim. As others have already said, then you need to know how much room is available on the front fork and rear part of the frame. What might be safe might not fit inside the frame or between the brakes if it has rim brakes.