How to determine the appropriate investment allocation for your age

Investing is an important part of building wealth and achieving financial security, but determining the appropriate investment allocation for your age and risk tolerance can be a challenging task. According to a general rule of thumb, you should allocate a certain amount of your portfolio to stocks and the rest to bonds by deducting your age from 100. For example, a 30-year-portfolio old's ought to consist of 70% stocks and 30% bonds. This guideline might not, however, apply to everyone. When making any financial decisions, it's important to take your investing goals, risk tolerance, and personal circumstances into account. You can also discover the ideal investment allocation for your age and goals by speaking with a financial counselor.

I am not sure how to calculate this but we need to invest that amount without which we can stay for a long term and for investment we should look for a long term investment only