The amount of time that passes before ejaculation is very different for each person, and what is "normal" can be different for each person. Usually, most men ejaculate a few minutes after starting to be sexual. There is, however, a lot of variation, and some people may last shorter or longer times.
If you regularly ejaculate before you want to, usually within one minute of entry, you may have premature ejaculation. People should talk to a healthcare worker if this becomes a problem that causes stress or relationship problems. It's important to know that there is no set "normal" length of sexual action. Age, stress, and general health can all affect when a man ejaculates. Talking to your partner about your worries and getting advice from a health care provider can help you deal with them and look for possible answers.