Most advice will suggest that you keep the length of your resume to a single page, and if you have limited relevant experience, this is still recommended. Less than ten years of experience in an appropriate field should mean that keeping to one page is easily achievable. This should also be considered if you have remained with the same employer for most of your career, or if you are pursuing a new career path and your previous jobs have no (or little) relevance to your new role.
However, in some cases, one page might not be enough. If you have a large number of relevant professional qualifications, or extensive experience within your field of work, you will need more space in order to make these facts known to your prospective employer. A second page would therefore be advisable, but make sure they are numbered. Ensure that your name and contact details are on both pages, just in case they become separated.
Very rare cases might benefit from an even longer resume. Don’t consider going over two pages unless you have very extensive experience, particularly at a senior level, or are in a field that encourages continued professional development and therefore hold many qualifications. This, along with publications in professional journals, might require a third page in order to fully highlight your achievements.
However, you should be aware that the majority of resumes will only be looked at very briefly, as employers may have large numbers of applications to screen. Your strongest points should be on the first page, where they will immediately be visible. If you are invited for an interview, it may be read more carefully, but this does not always happen.
Don’t be tempted to squeeze everything onto one page by making the text too small or the lines closer together. It is better to have a resume that is clear and easy to read at a glance. If there is only a line or two on the next page, it may be possible to condense some of the information that you have included, or to remove details about an earlier role that might be less important.
So, there is no fixed rule about resume length, other than it should be as short as possible, while still being long enough to cover your experience. The key is to be concise, and to keep it focused and relevant.