Deciding the magnification of your binoculars is a personal choice, but will usually come down to what you want to use your binoculars for. For example, 10x are great for viewing wildlife at a distance, stargazing will be better with a 20x or similar.
Test out a range of models, and see how you feel. The size of your hands, face shape, how your eyes naturally focus, and strength of your arms can all impact your experience.
To find out what binoculars are best for specific activities, such as marine, astronomy and sporting, check out our guide to The Best Binoculars in 2019.